WorldWideScience

Sample records for aquatic ecosystem including

  1. Export of aquatic productivity, including highly unsaturated fatty acids, to terrestrial ecosystems via Odonata.

    Science.gov (United States)

    Popova, Olga N; Haritonov, Anatoly Y; Sushchik, Nadezhda N; Makhutova, Olesia N; Kalachova, Galina S; Kolmakova, Anzhelika A; Gladyshev, Michail I

    2017-03-01

    Based on 31-year field study of the abundance and biomass of 18 species of odonates in the Barabinsk Forest-Steppe (Western Siberia, Russia), we quantified the contribution of odonates to the export of aquatic productivity to surrounding terrestrial landscape. Emergence varied from 0.8 to 4.9g of wet biomass per m(2) of land area per year. Average export of organic carbon was estimated to be 0.30g·m(-2)·year(-1), which is comparable with the average production of herbivorous terrestrial insects in temperate grasslands. Moreover, in contrast to terrestrial insects, emerging odonates contained high quantities of highly unsaturated fatty acids (HUFA), namely eicosapentaenoic acid (20:5n-3, EPA), and docosahexaenoic acid (22:6n-3, DHA), which are known to be essential for many terrestrial animals, especially for birds. The export of EPA+DHA by odonates was found to be 1.92-11.76mg·m(-2)·year(-1), which is equal to an average general estimation of the export of HUFA by emerging aquatic insects. Therefore, odonates appeared to be a quantitatively and qualitatively important conduit of aquatic productivity to forest-steppe ecosystem.

  2. Development of resource shed delineation in aquatic ecosystems

    Science.gov (United States)

    Environmental issues in aquatic ecosystems of high management priority involve spatially explicit phenomena that occur over vast areas. A "landscape" perspective is thus necessary, including an understanding of how ecological phenomena at a local scale are affected by physical fo...

  3. Systems and Cycles: Learning about Aquatic Ecosystems

    Science.gov (United States)

    Hmelo-Silver, Cindy E.; Jordan, Rebecca; Eberbach, Catherine; Rugaber, Spencer; Goel, Ashok

    2011-01-01

    In this research, the authors present both the design and preliminary testing of a technology-intensive classroom intervention designed to support middle schools students' understanding of an aquatic ecosystem. The goals of their intervention are to help learners develop deep understanding of ecosystems and to use tools that make the relationships…

  4. Ecology in Small Aquatic Ecosystems

    DEFF Research Database (Denmark)

    Andersen, Mikkel René

    Small ecosystems are many-fold more abundant than their larger counterparts. Both on regional and global scale small lakes outnumber medium and large lakes and account for a much larger surface area. Small streams are also far more common than rivers. Despite their abundance small ecosystems are ...

  5. Algal Bloom in Aquatic Ecosystems-an Overview

    OpenAIRE

    M. Ghorbani; S.A. Mirbagheri; A. H. Hasani; S. M. Monavari; J.Nouri

    2014-01-01

    Algae play an important role in all aquatic ecosystems by providing all living organisms of water bodies with preliminary nutrients and energy required. However, abnormal and excessive algal growth so-called algal bloom would be detrimental as much. Given the importance of algae in aquatic environment as well as their sensitivity to environmental changes, algal measurements are of key components of water quality monitoring programs. The algal blooms could include a variety of adverse impacts...

  6. Aquatic biodiversity in forests: A weak link in ecosystem services resilience

    Science.gov (United States)

    Penaluna, Brooke E.; Olson, Deanna H.; Flitcroft, Rebecca L; Weber, Matthew A.; Bellmore, J. Ryan; Wondzell, Steven M.; Dunham, Jason; Johnson, Sherri L.; Reeves, Gordon H.

    2016-01-01

    The diversity of aquatic ecosystems is being quickly reduced on many continents, warranting a closer examination of the consequences for ecological integrity and ecosystem services. Here we describe intermediate and final ecosystem services derived from aquatic biodiversity in forests. We include a summary of the factors framing the assembly of aquatic biodiversity in forests in natural systems and how they change with a variety of natural disturbances and human-derived stressors. We consider forested aquatic ecosystems as a multi-state portfolio, with diverse assemblages and life-history strategies occurring at local scales as a consequence of a mosaic of habitat conditions and past disturbances and stressors. Maintaining this multi-state portfolio of assemblages requires a broad perspective of ecosystem structure, various functions, services, and management implications relative to contemporary stressors. Because aquatic biodiversity provides multiple ecosystem services to forests, activities that compromise aquatic ecosystems and biodiversity could be an issue for maintaining forest ecosystem integrity. We illustrate these concepts with examples of aquatic biodiversity and ecosystem services in forests of northwestern North America, also known as Northeast Pacific Rim. Encouraging management planning at broad as well as local spatial scales to recognize multi-state ecosystem management goals has promise for maintaining valuable ecosystem services. Ultimately, integration of information from socio-ecological ecosystems will be needed to maintain ecosystem services derived directly and indirectly from forest aquatic biota.

  7. Economic valuation of aquatic ecosystem services in developing countries

    DEFF Research Database (Denmark)

    Korsgaard, Louise; Schou, Jesper S.

    2010-01-01

    -the silent water user. A promising way of placing aquatic ecosystems on the water agenda is by economic valuation of services sustained by ecosystems. In developing countries, the livelihoods of rural people often depend directly on the provision of aquatic ecosystem services. In such situations, economic...... valuation of ecosystem services becomes particularly challenging. This paper reviews recent literature on economic valuation of aquatic ecosystem services in developing countries. "Market price" is the most widespread method used for valuating marketed ecosystem services in developing countries. "Cost based......" and "revealed preference" methods are frequently used when ecosystem services are non-marketed. A review of 27 existing valuation studies reveals a considerable range of estimated total economic value of aquatic ecosystem services in developing countries, that is from US$30 to 3,000/ha/year. The paper concludes...

  8. Exploring, exploiting and evolving diversity of aquatic ecosystem models

    DEFF Research Database (Denmark)

    Janssen, Annette B. G.; Arhonditsis, George B.; Beusen, Arthur

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality m...

  9. A community-based framework for aquatic ecosystem models

    DEFF Research Database (Denmark)

    Trolle, Didde; Hamilton, D. P.; Hipsey, M. R.;

    2012-01-01

    aim to (i) advance collaboration within the aquatic ecosystem modelling community, (ii) enable increased use of models for research, policy and ecosystem-based management, (iii) facilitate a collective framework using common (standardised) code to ensure that model development is incremental, (iv......Here, we communicate a point of departure in the development of aquatic ecosystem models, namely a new community-based framework, which supports an enhanced and transparent union between the collective expertise that exists in the communities of traditional ecologists and model developers. Through...... a literature survey, we document the growing importance of numerical aquatic ecosystem models while also noting the difficulties, up until now, of the aquatic scientific community to make significant advances in these models during the past two decades. Through a common forum for aquatic ecosystem modellers we...

  10. Global ecological impacts of invasive species in aquatic ecosystems.

    Science.gov (United States)

    Gallardo, Belinda; Clavero, Miguel; Sánchez, Marta I; Vilà, Montserrat

    2016-01-01

    The introduction of invasive species, which often differ functionally from the components of the recipient community, generates ecological impacts that propagate along the food web. This review aims to determine how consistent the impacts of aquatic invasions are across taxa and habitats. To that end, we present a global meta-analysis from 151 publications (733 cases), covering a wide range of invaders (primary producers, filter collectors, omnivores and predators), resident aquatic community components (macrophytes, phytoplankton, zooplankton, benthic invertebrates and fish) and habitats (rivers, lakes and estuaries). Our synthesis suggests a strong negative influence of invasive species on the abundance of aquatic communities, particularly macrophytes, zooplankton and fish. In contrast, there was no general evidence for a decrease in species diversity in invaded habitats, suggesting a time lag between rapid abundance changes and local extinctions. Invaded habitats showed increased water turbidity, nitrogen and organic matter concentration, which are related to the capacity of invaders to transform habitats and increase eutrophication. The expansion of invasive macrophytes caused the largest decrease in fish abundance, the filtering activity of filter collectors depleted planktonic communities, omnivores (including both facultative and obligate herbivores) were responsible for the greatest decline in macrophyte abundance, and benthic invertebrates were most negatively affected by the introduction of new predators. These impacts were relatively consistent across habitats and experimental approaches. Based on our results, we propose a framework of positive and negative links between invasive species at four trophic positions and the five different components of recipient communities. This framework incorporates both direct biotic interactions (predation, competition, grazing) and indirect changes to the water physicochemical conditions mediated by invaders (habitat

  11. Microplastics in aquatic environments: Implications for Canadian ecosystems.

    Science.gov (United States)

    Anderson, Julie C; Park, Bradley J; Palace, Vince P

    2016-11-01

    Microplastics have been increasingly detected and quantified in marine and freshwater environments, and there are growing concerns about potential effects in biota. A literature review was conducted to summarize the current state of knowledge of microplastics in Canadian aquatic environments; specifically, the sources, environmental fate, behaviour, abundance, and toxicological effects in aquatic organisms. While we found that research and publications on these topics have increased dramatically since 2010, relatively few studies have assessed the presence, fate, and effects of microplastics in Canadian water bodies. We suggest that efforts to determine aquatic receptors at greatest risk of detrimental effects due to microplastic exposure, and their associated contaminants, are particularly warranted. There is also a need to address the gaps identified, with a particular focus on the species and conditions found in Canadian aquatic systems. These gaps include characterization of the presence of microplastics in Canadian freshwater ecosystems, identifying key sources of microplastics to these systems, and evaluating the presence of microplastics in Arctic waters and biota.

  12. Risk Assessment Considerations for Veterinary Medicines in Aquatic Ecosystems

    Science.gov (United States)

    This chapter provides a critical evaluation of prospective and retrospective risk assessment approaches for veterinary medicines in aquatic ecosystems and provides recommendations for possible alternative approaches for hazard characterization.

  13. An automated platform for phytoplankton ecology and aquatic ecosystem monitoring.

    Science.gov (United States)

    Pomati, Francesco; Jokela, Jukka; Simona, Marco; Veronesi, Mauro; Ibelings, Bas W

    2011-11-15

    High quality monitoring data are vital for tracking and understanding the causes of ecosystem change. We present a potentially powerful approach for phytoplankton and aquatic ecosystem monitoring, based on integration of scanning flow-cytometry for the characterization and counting of algal cells with multiparametric vertical water profiling. This approach affords high-frequency data on phytoplankton abundance, functional traits and diversity, coupled with the characterization of environmental conditions for growth over the vertical structure of a deep water body. Data from a pilot study revealed effects of an environmental disturbance event on the phytoplankton community in Lake Lugano (Switzerland), characterized by a reduction in cytometry-based functional diversity and by a period of cyanobacterial dominance. These changes were missed by traditional limnological methods, employed in parallel to high-frequency monitoring. Modeling of phytoplankton functional diversity revealed the importance of integrated spatiotemporal data, including circadian time-lags and variability over the water column, to understand the drivers of diversity and dynamic processes. The approach described represents progress toward an automated and trait-based analysis of phytoplankton natural communities. Streamlining of high-frequency measurements may represent a resource for understanding, modeling and managing aquatic ecosystems under impact of environmental change, yielding insight into processes governing phytoplankton community resistance and resilience.

  14. Review on environmental alterations propagating from aquatic to terrestrial ecosystems.

    Science.gov (United States)

    Schulz, Ralf; Bundschuh, Mirco; Gergs, René; Brühl, Carsten A; Diehl, Dörte; Entling, Martin H; Fahse, Lorenz; Frör, Oliver; Jungkunst, Hermann F; Lorke, Andreas; Schäfer, Ralf B; Schaumann, Gabriele E; Schwenk, Klaus

    2015-12-15

    Terrestrial inputs into freshwater ecosystems are a classical field of environmental science. Resource fluxes (subsidy) from aquatic to terrestrial systems have been less studied, although they are of high ecological relevance particularly for the receiving ecosystem. These fluxes may, however, be impacted by anthropogenically driven alterations modifying structure and functioning of aquatic ecosystems. In this context, we reviewed the peer-reviewed literature for studies addressing the subsidy of terrestrial by aquatic ecosystems with special emphasis on the role that anthropogenic alterations play in this water-land coupling. Our analysis revealed a continuously increasing interest in the coupling of aquatic to terrestrial ecosystems between 1990 and 2014 (total: 661 studies), while the research domains focusing on abiotic (502 studies) and biotic (159 studies) processes are strongly separated. Approximately 35% (abiotic) and 25% (biotic) of the studies focused on the propagation of anthropogenic alterations from the aquatic to the terrestrial system. Among these studies, hydromorphological and hydrological alterations were predominantly assessed, whereas water pollution and invasive species were less frequently investigated. Less than 5% of these studies considered indirect effects in the terrestrial system e.g. via food web responses, as a result of anthropogenic alterations in aquatic ecosystems. Nonetheless, these very few publications indicate far-reaching consequences in the receiving terrestrial ecosystem. For example, bottom-up mediated responses via soil quality can cascade over plant communities up to the level of herbivorous arthropods, while top-down mediated responses via predatory spiders can cascade down to herbivorous arthropods and even plants. Overall, the current state of knowledge calls for an integrated assessment on how these interactions within terrestrial ecosystems are affected by propagation of aquatic ecosystem alterations. To fill

  15. An automated platform for phytoplankton ecology and aquatic ecosystem monitoring

    NARCIS (Netherlands)

    Pomati, F.; Jokela, J.; Simona, M.; Veronesi, M.; Ibelings, B.W.

    2011-01-01

    High quality monitoring data are vital for tracking and understanding the causes of ecosystem change. We present a potentially powerful approach for phytoplankton and aquatic ecosystem monitoring, based on integration of scanning flow-cytometry for the characterization and counting of algal cells wi

  16. Ecotoxicological Studies on Egyptian Aquatic Ecosystems

    Institute of Scientific and Technical Information of China (English)

    Sameeh A. Mansour

    2004-01-01

    @@ Within the framework of a national research project, Egyptianaquatic ecosystems represented by Lakes of Qarun and Wadi El-Rayan,aswell as other related ecosystems, were subjected to certain toxicologicalstudies.

  17. A model for an aquatic ecosystem

    Science.gov (United States)

    Qiao, Han Li; Venturino, Ezio

    2016-06-01

    An ecosystem made of nutrients, plants, detritus and dissolved oxygen is presented. Its equilibria are established. Sufficient conditions for the existence of the coexistence equilibrium are derived and its feasibility is discussed in every detail.

  18. Measurement of undisturbed di-nitrogen emissions from aquatic ecosystems

    Science.gov (United States)

    Qin, Shuping, Clough, Timothy, Lou, Jiafa; Hu, Chunsheng; Oenema, Oene; Wrage-Mönnig, Nicole; Zhang, Yuming

    2016-04-01

    Increased production of reactive nitrogen (Nr) from atmospheric di-nitrogen (N2) during the last century has greatly contributed to increased food production1-4. However, enriching the biosphere with Nr through N fertilizer production, combustion, and biological N2 fixation has also caused a series of negative effects on global ecosystems 5,6, especially aquatic ecosystems7. The main pathway converting Nr back into the atmospheric N2 pool is the last step of the denitrification process, i.e., the reduction of nitrous oxide (N2O) into N2 by micro-organisms7,8. Despite several attempts9,10, there is not yet an accurate, fast and direct method for measuring undisturbed N2 fluxes from denitrification in aquatic sediments at the field scale11-14. Such a method is essential to study the feedback of aquatic ecosystems to Nr inputs1,2,7. Here we show that the measurement of both N2O emission and its isotope signature can be used to infer the undisturbed N2 fluxes from aquatic ecosystems. The microbial reduction of N2O increases the natural abundance of 15N-N2O relative to 14N-N2O (δ15N-N2O). We observed linear relationships between δ15N-N2O and the logarithmic transformed N2O/(N2+N2O) emission ratios. Through independent measurements, we verified that the undisturbed N2 flux from aquatic ecosystems can be inferred from measurements of N2O emissions and the δ15N-N2O signature. Our method allows the determination of field-scale N2 fluxes from undisturbed aquatic ecosystems, and thereby allows model predictions of denitrification rates to be tested. The undisturbed N2 fluxes observed are almost one order of magnitude higher than those estimated by the traditional method, where perturbation of the system occurs, indicating that the ability of aquatic ecosystems to remove Nr may have been severely underestimated.

  19. 76 FR 55060 - Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor...

    Science.gov (United States)

    2011-09-06

    ... AGENCY Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor... of Availability. SUMMARY: EPA is releasing a final report entitled, Aquatic Ecosystems, Water Quality... with identifying, calculating, and mapping indicators of the relative vulnerability of water...

  20. 76 FR 10892 - Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor...

    Science.gov (United States)

    2011-02-28

    ... AGENCY Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor.... SUMMARY: EPA is announcing the release of the draft report titled, ``Aquatic Ecosystems, Water Quality... relative vulnerability of water quality and aquatic ecosystems, across the United States, to the...

  1. Production of EPA and DHA in aquatic ecosystems and their transfer to the land.

    Science.gov (United States)

    Gladyshev, Michail I; Sushchik, Nadezhda N; Makhutova, Olesia N

    2013-12-01

    Most omnivorous animals, including humans, have to some degree relied on physiologically important polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from food. Only some taxa of microalgae, rather than higher plants can synthesize de novo high amounts of EPA and DHA. Once synthesized by microalgae, PUFA are transferred through trophic chain to organisms of higher levels. Thus, aquatic ecosystems play the unique role in the Biosphere as the principal source of EPA and DHA for most omnivorous animals, including inhabitants of terrestrial ecosystems. PUFA are transferred from aquatic to terrestrial ecosystems through riparian predators, drift of carrion and seaweeds, emergence of amphibiotic insects, and water birds. The essential PUFA are transferred through trophic chains with about twice higher efficiency than bulk carbon. Thereby, PUFA are accumulated, rather than diluted in biomass of organisms of higher trophic levels, e.g., in fish. Mankind is faced with a severe deficiency of EPA and DHA in diet. Although additional sources of PUFA supply for humans, such as aquaculture, biotechnology of microorganisms and transgenic terrestrial oil-seed producing plants are developed, natural fish production of aquatic ecosystems will remain one of the main sources of EPA and DHA for humans. Aquatic ecosystems have to be protected from anthropogenic impacts, such as eutrophication, pollution and warming, which reduce PUFA production.

  2. Herbivore regulation of plant abundance in aquatic ecosystems.

    Science.gov (United States)

    Wood, Kevin A; O'Hare, Matthew T; McDonald, Claire; Searle, Kate R; Daunt, Francis; Stillman, Richard A

    2017-05-01

    Herbivory is a fundamental process that controls primary producer abundance and regulates energy and nutrient flows to higher trophic levels. Despite the recent proliferation of small-scale studies on herbivore effects on aquatic plants, there remains limited understanding of the factors that control consumer regulation of vascular plants in aquatic ecosystems. Our current knowledge of the regulation of primary producers has hindered efforts to understand the structure and functioning of aquatic ecosystems, and to manage such ecosystems effectively. We conducted a global meta-analysis of the outcomes of plant-herbivore interactions using a data set comprised of 326 values from 163 studies, in order to test two mechanistic hypotheses: first, that greater negative changes in plant abundance would be associated with higher herbivore biomass densities; second, that the magnitude of changes in plant abundance would vary with herbivore taxonomic identity. We found evidence that plant abundance declined with increased herbivore density, with plants eliminated at high densities. Significant between-taxa differences in impact were detected, with insects associated with smaller reductions in plant abundance than all other taxa. Similarly, birds caused smaller reductions in plant abundance than echinoderms, fish, or molluscs. Furthermore, larger reductions in plant abundance were detected for fish relative to crustaceans. We found a positive relationship between herbivore species richness and change in plant abundance, with the strongest reductions in plant abundance reported for low herbivore species richness, suggesting that greater herbivore diversity may protect against large reductions in plant abundance. Finally, we found that herbivore-plant nativeness was a key factor affecting the magnitude of herbivore impacts on plant abundance across a wide range of species assemblages. Assemblages comprised of invasive herbivores and native plant assemblages were associated with

  3. Challenges of deriving a complete biosphere greenhouse gas balance through integration of terrestrial and aquatic ecosystems

    Science.gov (United States)

    Peichl, Matthias

    2013-04-01

    Past research efforts have mostly focused on separately investigating the exchange of greenhouse gases (GHGs) within the limits of different terrestrial and aquatic ecosystem types. More recently however, it has been recognized that GHG exchanges and budgets are not limited to boundaries of the terrestrial or aquatic biosphere components and instead are often tightly linked amongst the different ecosystem types. Primarily the aquatic production and export of GHGs due to substrate supply or discharge from surrounding terrestrial ecosystems play a major role in regional GHG budgets. Understanding the mechanisms and drivers of this connectivity between different terrestrial and aquatic ecosystem GHG exchanges is therefore necessary to develop landscape-level GHG budgets and to understand their sensitivity to disturbances of the biosphere. Moreover, the exchange of carbon dioxide (CO2) as the most important GHG species has been the primary research objective with regards to obtaining better estimates of the carbon sequestration potential of the biosphere. However, methane (CH4) and nitrous oxide (N2O) emissions may offset CO2 sinks and considerably affect the complete GHG balance in both terrestrial and aquatic systems. Including their contribution and improved knowledge on the dynamics of these two gas species is therefore essential for complete GHG budget estimates. At present, the integration of terrestrial and aquatic GHG exchanges toward landscape GHG budgets poses numerous challenges. These include the need for a better knowledge of i) the contribution of CH4 and N2O to the GHG budgets within contrasting terrestrial (forests, peatlands, grasslands, croplands) and aquatic (lake, streams) ecosystems when integrated over a full year, ii) the effect of ecosystem properties (e.g. age and/or development stage, size of water body) on the GHG balance, iii) the impact of management effects (e.g. nitrogen fertilizer application), iv) differences among climate regions and v

  4. Aquatic ecosystem characterisation strategy at a repository site

    Energy Technology Data Exchange (ETDEWEB)

    Kangasniemi, Ville; Ikonen, Ari T.K. [Environmental Research and Assessment EnviroCase, Ltd., Hallituskatu 1 D 4, 28100 Pori (Finland); Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Laulukuja 4, 00420 Helsinki (Finland); Kirkkala, Teija [Pyhaejaervi Institute, Sepaentie 7, 27500 Kauttua (Finland); Koivunen, Sari [Water and Environment Research of South-West Finland, Telekatu 16, 20360 Turku (Finland)

    2014-07-01

    Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel disposal. According to regulatory requirements, the safety assessment for the repository should have an assessment timeframe of several millennia. Due to the post-glacial land uplift, the relatively shallow sea areas around Olkiluoto Island will change gradually to lakes, rivers and terrestrial areas. As there are no limnic systems at present Olkiluoto site, the reference area was delineated and reference lakes and rivers were selected as an analogue. For the modelling of the transport and accumulation of possible radionuclide releases in the surface environment, aquatic ecosystems were identified and divided into biotopes. Despite the number of available templates, the division of aquatic environment for the biosphere assessment of the Olkiluoto spent fuel repository was necessary to made separately. In this contribution, the processes behind the identification of aquatic ecosystems (e.g. legislation, physical and chemical properties) together with the biotope selection methodology (e.g. light and bottom conditions) and the challenges related to the amount of variable input parameters for each biotope in the modelling are presented. (authors)

  5. Fire effects on aquatic ecosystems: an assessment of the current state of the science

    Science.gov (United States)

    Rebecca J. Bixby,; Scott D. Cooper,; Gresswell, Bob; Lee E. Brown,; Clifford N. Dahm,; Kathleen A. Dwire,

    2015-01-01

    Fire is a prevalent feature of many landscapes and has numerous and complex effects on geological, hydrological, ecological, and economic systems. In some regions, the frequency and intensity of wildfire have increased in recent years and are projected to escalate with predicted climatic and landuse changes. In addition, prescribed burns continue to be used in many parts of the world to clear vegetation for development projects, encourage desired vegetation, and reduce fuel loads. Given the prevalence of fire on the landscape, authors of papers in this special series examine the complexities of fire as a disturbance shaping freshwater ecosystems and highlight the state of the science. These papers cover key aspects of fire effects that range from vegetation loss and recovery in watersheds to effects on hydrology and water quality with consequences for communities (from algae to fish), food webs, and ecosystem processes (e.g., organic matter subsidies, nutrient cycling) across a range of scales. The results presented in this special series of articles expand our knowledge of fire effects in different biomes, water bodies, and geographic regions, encompassing aquatic population, community, and ecosystem responses. In this overview, we summarize each paper and emphasize its contributions to knowledge on fire ecology and freshwater ecosystems. This overview concludes with a list of 7 research foci that are needed to further our knowledge of fire effects on aquatic ecosystems, including research on: 1) additional biomes and geographic regions; 2) additional habitats, including wetlands and lacustrine ecosystems; 3) different fire severities, sizes, and spatial configurations; and 4) additional response variables (e.g., ecosystem processes) 5) over long (>5 y) time scales 6) with more rigorous study designs and data analyses, and 7) consideration of the effects of fire management practices and policies on aquatic ecosystems.

  6. Methodological tests of a heterotrophy index for aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    R. M. Antonio

    Full Text Available Experiments in glucose mineralization were carried out to investigate the effects caused by natural forcing functions on both the decomposition rates and heterotrophy capacity of aquatic ecosystems. In addition, the methodology used could show connections between mineralization rates measured in both laboratory and field work with those measured in aquatic ecosystems. Water samples from Infernão lagoon (21º35'S and 47º51'W were collected, filtered, enriched with glucose, and incubated under aerobic and anaerobic conditions. The glucose concentration variation, dissolved oxygen (DO consumption, pH, electric conductivity, and total CO2 amount in the water were determined for sixteen days. In the period with intense oxygen consumption there was also an evident glucose demand and the dissolved oxygen consumption rate was approximately the same as that for glucose mineralization. The process in the aerobic chambers was 2.2 times faster than that in the anaerobic chambers. An initial acidification of the water samples, probably due to microbial carbonic acid liberation, was noted. A rise in pH values was also observed at the end of the process. The electric conductivity was low for both aerobic and anaerobic chambers, indicating a probable ion uptake by microbial organisms due to the presence of carbon sources. The glucose content variations corresponded to both CO2 formation and dissolved oxygen consumption. It was estimated that 19.4% of the initial glucose content turned into CO2 and the remaining 80.6% into humic compounds and microbial biomass. This experiment showed that glucose can be used as a substrate indicating the heterotrophy of a given aquatic ecosystem.

  7. Methodological tests of a heterotrophy index for aquatic ecosystems.

    Science.gov (United States)

    Antonio, R M; Bianchini Júnior, I

    2003-08-01

    Experiments in glucose mineralization were carried out to investigate the effects caused by natural forcing functions on both the decomposition rates and heterotrophy capacity of aquatic ecosystems. In addition, the methodology used could show connections between mineralization rates measured in both laboratory and field work with those measured in aquatic ecosystems. Water samples from Infernão lagoon (21 degrees 35'S and 47 degrees 51'W) were collected, filtered, enriched with glucose, and incubated under aerobic and anaerobic conditions. The glucose concentration variation, dissolved oxygen (DO) consumption, pH, electric conductivity, and total CO2 amount in the water were determined for sixteen days. In the period with intense oxygen consumption there was also an evident glucose demand and the dissolved oxygen consumption rate was approximately the same as that for glucose mineralization. The process in the aerobic chambers was 2.2 times faster than that in the anaerobic chambers. An initial acidification of the water samples, probably due to microbial carbonic acid liberation, was noted. A rise in pH values was also observed at the end of the process. The electric conductivity was low for both aerobic and anaerobic chambers, indicating a probable ion uptake by microbial organisms due to the presence of carbon sources. The glucose content variations corresponded to both CO2 formation and dissolved oxygen consumption. It was estimated that 19.4% of the initial glucose content turned into CO2 and the remaining 80.6% into humic compounds and microbial biomass. This experiment showed that glucose can be used as a substrate indicating the heterotrophy of a given aquatic ecosystem.

  8. 75 FR 18499 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2010-04-12

    ... AGENCY The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian... Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields'' (EPA/600/R-09/138A) and (2... Fills on Aquatic Ecosystems of the Central Appalachian Coalfields'' and ``A Field-based Aquatic...

  9. Environmental bacteriophages : viruses of microbes in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Télesphore eSIME - NGANDO

    2014-07-01

    Full Text Available Since the discovery 2-3 decades ago that viruses of microbes are abundant in marine ecosystems, viral ecology has grown increasingly to reach the status of a full scientific discipline in environmental sciences. A dedicated ISVM society, the International Society for Viruses of Microorganisms (http://www.isvm.org/, was recently launched. Increasing studies in viral ecology are sources of novel knowledge related to the biodiversity of living things, the functioning of ecosystems, and the evolution of the cellular world. This is because viruses are perhaps the most diverse, abundant, and ubiquitous biological entities in the biosphere, although local environmental conditions enrich for certain viral types through selective pressure. They exhibit various lifestyles that intimately depend on the deep-cellular mechanisms, and are ultimately replicated by members of all three domains of cellular life (Bacteria, Eukarya, Archaea, as well as by giant viruses of some eukaryotic cells. This establishes viral parasites as microbial killers but also as cell partners or metabolic manipulators in microbial ecology. The present chapter sought to review the literature on the diversity and functional roles of viruses of microbes in environmental microbiology, focusing primarily on prokaryotic viruses (i.e. phages in aquatic ecosystems, which form the bulk of our knowledge in modern environmental viral ecology.

  10. Environmental behavior of linear alkylbenzene sulfonate (LAS) in aquatic ecosystem

    Science.gov (United States)

    Zhang, Yongyuan; Tan, Yuyun; Korte, F.

    1991-03-01

    LAS degradation rate in Donghu Lake water under aerobic was much faster than under anaerobic condition. The half life of LAS in aerobic and anaerobic environment was 3.2 days and 57 days, respectively. The degradation rate at 25 27°C was approximately 20 times higher than that at 1.5 3.5 °C. In a laboratory model aquatic ecosystem, two stages of bioconcentration in fish, daphnia and snail were observed. The first stage, on second day exposure, resulted from accumulation of intact LAS, and the second stage, on 16th day exposure, was due to metabolites. The bioconcentration factor (BCF) of LAS was extremely low in the muscle of hybrid carp (0.64), but rather high (2485) in the gall bladder.

  11. Controlled Environments Enable Adaptive Management in Aquatic Ecosystems Under Altered Environments

    Science.gov (United States)

    Bubenheim, David L.

    2016-01-01

    Ecosystems worldwide are impacted by altered environment conditions resulting from climate, drought, and land use changes. Gaps in the science knowledge base regarding plant community response to these novel and rapid changes limit both science understanding and management of ecosystems. We describe how CE Technologies have enabled the rapid supply of gap-filling science, development of ecosystem simulation models, and remote sensing assessment tools to provide science-informed, adaptive management methods in the impacted aquatic ecosystem of the California Sacramento-San Joaquin River Delta. The Delta is the hub for California's water, supplying Southern California agriculture and urban communities as well as the San Francisco Bay area. The changes in environmental conditions including temperature, light, and water quality and associated expansion of invasive aquatic plants negatively impact water distribution and ecology of the San Francisco Bay/Delta complex. CE technologies define changes in resource use efficiencies, photosynthetic productivity, evapotranspiration, phenology, reproductive strategies, and spectral reflectance modifications in native and invasive species in response to altered conditions. We will discuss how the CE technologies play an enabling role in filling knowledge gaps regarding plant response to altered environments, parameterization and validation of ecosystem models, development of satellite-based, remote sensing tools, and operational management strategies.

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

    DEFF Research Database (Denmark)

    Stief, P.

    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) ecosystem engineering, (ii) grazing, and (iii) symbiosis. Their specific contributions to the turnover of fixed nitrogen...... that contributes to global warming. Overall, benthic macrofauna intensifies the coupling between benthos, pelagial, and atmosphere through enhanced turnover and transport of nitrogen....

  13. 75 FR 39934 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2010-07-13

    ... AGENCY The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian...) ``The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian.... ADDRESSES: The draft reports, ``The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems...

  14. 75 FR 51058 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2010-08-18

    ... AGENCY The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian... Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields.... ADDRESSES: The draft reports, ``The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems...

  15. 75 FR 30393 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2010-06-01

    ... AGENCY The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian... Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields.... ADDRESSES: The draft reports, ``The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems...

  16. 76 FR 30938 - The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

    Science.gov (United States)

    2011-05-27

    ... AGENCY The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian... Mines and Valley Fills on Aquatic Ecosystems of the Central Appalachian Coalfields (EPA/600/R-09/138F... The Effects of Mountaintop Mines and Valley Fills on Aquatic Ecosystems of the Central...

  17. Effects of micro- and nanoplastics on aquatic ecosystems: Current research trends and perspectives.

    Science.gov (United States)

    Chae, Yooeun; An, Youn-Joo

    2017-02-17

    Contamination by bulk plastics and plastic debris is currently the one of the most serious environmental problems in aquatic ecosystems. In particular, small-scale plastic debris such as microplastics and nanoplastics has become leading contributors to the pollution of marine and freshwater ecosystems. Studies are investigating the impacts of micro-and nanoplastics on aquatic organisms and ecosystems worldwide. This review covers 83 studies that investigated the distribution of microplastics and the ecotoxicity of micro- and nanoplastics in marine and freshwater ecosystems. The studies indicated that micro-sized plastics and plastic debris were distributed at various concentrations in aquatic ecosystems around the world. They had various effects on the growth, development, behavior, reproduction, and mortality of aquatic animals. We discuss these studies in detail and suggest directions for future research.

  18. Scaling for Robust Assessment and Predictions of Aquatic Ecosystem Health

    Science.gov (United States)

    Abdul-Aziz, O.; Ishtiaq, K. S.

    2012-12-01

    This presentation demonstrates the development and applications of a unique scaling technique for robust assessment and predictions of aquatic ecosystem health. We developed scaling-based, robust empirical and semi-empirical models for standardizing grab samples of stream dissolved oxygen (DO) and for predicting (hindcasting and forecasting) stream DO time-series. A reference clock-time, single observation from the diurnal cycle is used as the scaling parameter to collapse hourly DO time-series of different days into a single diurnal curve, which is parameterized by developing an extended stochastic harmonic analysis (ESHA). The scaling technique was previously applied to develop an algorithm for converting grab samples of stream DO collected at any time of the day to a reference clock time. The research is extended to develop an algorithm for simulating the diurnal DO cycles at different stream sites from their corresponding single reference observations of the day. The scaling concept was tested for spatio-temporal robustness with hourly DO data for eight streams representing five distinct Level III Ecoregions of Minnesota. Estimated model parameters demonstrated notable robustness in time and space. Scaling is often used to develop robust modeling and application tools in many physical engineering disciplines. Presented research exemplifies utilization of the scaling concept in Ecological Engineering applications.

  19. Aquatic Ecosystem Enhancement at Mountaintop Mining Sites Symposium

    Energy Technology Data Exchange (ETDEWEB)

    Black, D. Courtney; Lawson, Peter; Morgan, John; Maggard, Randy; Schor, Horst; Powell, Rocky; Kirk, Ed. J.

    2000-01-12

    Welcome to this symposium which is part of the ongoing effort to prepare an Environmental Impact Statement (EIS) regarding mountaintop mining and valley fills. The EIS is being prepared by the U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, U.S. Office of Surface Mining, and U.S. Fish and Wildlife Service, in cooperation with the State of West Virginia. Aquatic Ecosystem Enhancement (AEE) at mountaintop mining sites is one of fourteen technical areas identified for study by the EIS Interagency Steering Committee. Three goals were identified in the AEE Work Plan: 1. Assess mining and reclamation practices to show how mining operations might be carried out in a way that minimizes adverse impacts to streams and other environmental resources and to local communities. Clarify economic and technical constraints and benefits. 2. Help citizens clarify choices by showing whether there are affordable ways to enhance existing mining, reclamation, mitigation processes and/or procedures. 3. Ide identify data needed to improve environmental evaluation and design of mining projects to protect the environment. Today’s symposium was proposed in the AEE Team Work Plans but coordinated planning for the event began September 15, 1999 when representatives from coal industry, environmental groups and government regulators met in Morgantown. The meeting participants worked with a facilitator from the Canaan Valley Institute to outline plans for the symposium. Several teams were formed to carry out the plans we outlined in the meeting.

  20. Aquatic polymers can drive pathogen transmission in coastal ecosystems.

    Science.gov (United States)

    Shapiro, Karen; Krusor, Colin; Mazzillo, Fernanda F M; Conrad, Patricia A; Largier, John L; Mazet, Jonna A K; Silver, Mary W

    2014-11-22

    Gelatinous polymers including extracellular polymeric substances (EPSs) are fundamental to biophysical processes in aquatic habitats, including mediating aggregation processes and functioning as the matrix of biofilms. Yet insight into the impact of these sticky molecules on the environmental transmission of pathogens in the ocean is limited. We used the zoonotic parasite Toxoplasma gondii as a model to evaluate polymer-mediated mechanisms that promote transmission of terrestrially derived pathogens to marine fauna and humans. We show that transparent exopolymer particles, a particulate form of EPS, enhance T. gondii association with marine aggregates, material consumed by organisms otherwise unable to access micrometre-sized particles. Adhesion to EPS biofilms on macroalgae also captures T. gondii from the water, enabling uptake of pathogens by invertebrates that feed on kelp surfaces. We demonstrate the acquisition, concentration and retention of T. gondii by kelp-grazing snails, which can transmit T. gondii to threatened California sea otters. Results highlight novel mechanisms whereby aquatic polymers facilitate incorporation of pathogens into food webs via association with particle aggregates and biofilms. Identifying the critical role of invisible polymers in transmission of pathogens in the ocean represents a fundamental advance in understanding and mitigating the health impacts of coastal habitat pollution with contaminated runoff.

  1. Solar energy development and aquatic ecosystems in the southwestern United States: potential impacts, mitigation, and research needs.

    Science.gov (United States)

    Grippo, Mark; Hayse, John W; O'Connor, Ben L

    2015-01-01

    The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.

  2. Adaptive management of large aquatic ecosystem recovery programs in the United States.

    Science.gov (United States)

    Thom, Ronald; St Clair, Tom; Burns, Rebecca; Anderson, Michael

    2016-12-01

    Adaptive management (AM) is being employed in a number of programs in the United States to guide actions to restore aquatic ecosystems because these programs are both expensive and are faced with significant uncertainties. Many of these uncertainties are associated with prioritizing when, where, and what kind of actions are needed to meet the objectives of enhancing ecosystem services and recovering threatened and endangered species. We interviewed nine large-scale aquatic ecosystem restoration programs across the United States to document the lessons learned from implementing AM. In addition, we recorded information on ecological drivers (e.g., endangered fish species) for the program, and inferred how these drivers reflected more generic ecosystem services. Ecosystem services (e.g., genetic diversity, cultural heritage), albeit not explicit drivers, were either important to the recovery or enhancement of the drivers, or were additional benefits associated with actions to recover or enhance the program drivers. Implementing programs using AM lessons learned has apparently helped achieve better results regarding enhancing ecosystem services and restoring target species populations. The interviews yielded several recommendations. The science and AM program must be integrated into how the overall restoration program operates in order to gain understanding and support, and effectively inform management decision-making. Governance and decision-making varied based on its particular circumstances. Open communication within and among agency and stakeholder groups and extensive vetting lead up to decisions. It was important to have an internal agency staff member to implement the AM plan, and a clear designation of roles and responsibilities, and long-term commitment of other involved parties. The most important management questions and information needs must be identified up front. It was imperative to clearly identify, link and continually reinforce the essential

  3. The basis for ecotoxicological concern in aquatic ecosystems contaminated by historical mercury mining.

    Science.gov (United States)

    Wiener, James G; Suchanek, Thomas H

    2008-12-01

    The Coast Range of California is one of five global regions that dominated historical production of mercury (Hg) until declining demand led to the economic collapse of the Hg-mining industry in the United States. Calcines, waste rock, and contaminated alluvium from inactive mine sites can release Hg (including methylmercury, MeHg) to the environment for decades to centuries after mining has ceased. Soils, water, and sediment near mines often contain high concentrations of total Hg (TotHg), and an understanding of the biogeochemical transformations, transport, and bioaccumulation of this toxic metal is needed to assess effects of these contaminated environments on humans and wildlife. We briefly review the environmental behavior and effects of Hg, providing a prelude to the subsequent papers in this Special Issue. Clear Lake is a northern California lake contaminated by wastes from the abandoned Sulphur Bank Mercury Mine, a U.S. Environmental Protection Agency Superfund Site. The primary toxicological problem with Hg in aquatic ecosystems is biotic exposure to MeHg, a highly toxic compound that readily bioaccumulates. Processes that affect the abundance of MeHg (including methylation and demethylation) strongly affect its concentration in all trophic levels of aquatic food webs. MeHg can biomagnify to high concentrations in aquatic food webs, and consumption of fish is the primary pathway for human exposure. Fish consumption advisories have been issued for many North American waters, including Clear Lake and other mine-impacted waters in California, as a means of decreasing MeHg exposure. Concerns about MeHg exposure in humans focus largely on developmental neurotoxicity to the fetus and children. Aquatic food webs are also an important pathway for MeHg exposure of wildlife, which can accumulate high, sometimes harmful, concentrations. In birds, wild mammals, and humans, MeHg readily passes to the developing egg, embryo, or fetus, life stages that are much more

  4. A carbon budget for the aquatic ecosystem above SFR in Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, L [Stockholm Univ. (Sweden). Dept. of Systems Ecology

    1999-07-01

    The potential hazards of radionuclide release to humans and the environment is regularly evaluated in safety assessments of SFR, the final repository for radioactive operational waste. SFR handles, since 1988, low and intermediate level nuclear waste from Swedish nuclear power plants, medical care attendance, industries and research laboratories and is located in the bedrock 50 meters under the seabed of Oeregrundsgrepen in the southern Bothnian Sea. This report presents a description of the aquatic ecosystem and a carbon budget for the area above SFR with the aim to include ecosystem dynamics in the present safety assessment of the repository (SAFE). The carbon budget will support SAFE by facilitating evaluations of transport and fate of radionuclides, primarily {sup 14}C, in case of a release from the repository and describe the ecosystem structure and function. Furthermore, {sup 14}C is the dose-dominant radionuclide in the repository which most likely will follow the general carbon flow in the ecosystem if there should be a release. The carbon budget was based on biomass and flow of carbon between thirteen functional groups (including POC and DOC) in the ecosystem above SFR and the results indicates that the organisms are self-sufficient on carbon and that the area exports carbon corresponding to approximately 50% of the annual primary production. The largest organic carbon pool is DOC (one and a half time larger than the total biomass) and the major functional organism groups are the macrophytes (37% of the total biomass), benthic macrofauna (36%), and the microphytes (11%). The soft bottom and phytobenthic communities seem to have important roles in the ecosystem since these communities comprise the main part of the living carbon in the studied area.

  5. Biogeochemical data from terrestrial and aquatic ecosystems in a periglacial catchment, West Greenland

    Science.gov (United States)

    Lindborg, Tobias; Rydberg, Johan; Tröjbom, Mats; Berglund, Sten; Johansson, Emma; Löfgren, Anders; Saetre, Peter; Nordén, Sara; Sohlenius, Gustav; Andersson, Eva; Petrone, Johannes; Borgiel, Micke; Kautsky, Ulrik; Laudon, Hjalmar

    2016-09-01

    Global warming is expected to be most pronounced in the Arctic where permafrost thaw and release of old carbon may provide an important feedback mechanism to the climate system. To better understand and predict climate effects and feedbacks on the cycling of elements within and between ecosystems in northern latitude landscapes, a thorough understanding of the processes related to transport and cycling of elements is required. A fundamental requirement to reach a better process understanding is to have access to high-quality empirical data on chemical concentrations and biotic properties for a wide range of ecosystem domains and functional units (abiotic and biotic pools). The aim of this study is therefore to make one of the most extensive field data sets from a periglacial catchment readily available that can be used both to describe present-day periglacial processes and to improve predictions of the future. Here we present the sampling and analytical methods, field and laboratory equipment and the resulting biogeochemical data from a state-of-the-art whole-ecosystem investigation of the terrestrial and aquatic parts of a lake catchment in the Kangerlussuaq region, West Greenland. This data set allows for the calculation of whole-ecosystem mass balance budgets for a long list of elements, including carbon, nutrients and major and trace metals. The data set is freely available and can be downloaded from PANGAEA: doi:10.1594/PANGAEA.860961.

  6. Assessing Sources of Stress to Aquatic Ecosystems: Using Biomarkers and Bioindicators to Characterize Exodure-Response Profiles of Anthropogenic Activities

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S.M.

    1999-03-29

    Establishing causal relationships between sources of environmental stressors and aquatic ecosystem health if difficult because of the many biotic and abiotic factors which can influence or modify responses of biological systems to stress, the orders of magnitude involved in extrapolation over both spatial and temporal scales, and compensatory mechanisms such as density-dependent responses that operate in populations. To address the problem of establishing causality between stressors and effects on aquatic systems, a diagnostic approach, based on exposure-response profiles for various anthropogenic activities, was developed to help identify sources of stress responsible for effects on aquatic systems at ecological significant levels of biological organization (individual, population, community). To generate these exposure-effects profiles, biomarkers of exposure were plotted against bioindicators of corresponding effects for several major anthropogenic activities including petrochemical , pulp and paper, domestic sewage, mining operations, land-development activities, and agricultural activities. Biomarkers of exposure to environmental stressors varied depending on the type of anthropogenic activity involved. Bioindicator effects, however, including histopathological lesions, bioenergetic status, individual growth, reproductive impairment, and community-level responses were similar among many of the major anthropogenic activities. This approach is valuable to help identify and diagnose sources of stressors in environments impacted by multiple stressors. By identifying the types and sources of environmental stressors, aquatic ecosystems can be more effectively protected and managed to maintain acceptable levels of environmental quality and ecosystem fitness.

  7. The role of aquatic ecosystems as reservoirs of antibiotic resistance.

    Science.gov (United States)

    Marti, Elisabet; Variatza, Eleni; Balcazar, Jose Luis

    2014-01-01

    Although antibiotic resistance has become a major threat to human health worldwide, this phenomenon has been largely overlooked in studies in environmental settings. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance, because they are frequently impacted by anthropogenic activities. This review focuses primarily on the emergence and dissemination of antibiotic resistance in the aquatic environment, with a special emphasis on the role of antibiotic resistance genes.

  8. Benefits of riparian forest for the aquatic ecosystem assessed at a large geographic scale

    Directory of Open Access Journals (Sweden)

    Van Looy K.

    2013-04-01

    Full Text Available Claimed benefits of riparian forest cover for the aquatic ecosystem include purification, thermal control, organic matter input and habitat provision, which may improve physicochemical and biotic quality. However, these beneficial effects might be flawed by multiple stressor conditions of intensive agriculture and urbanization in upstream catchments. We examined the relationship between riparian forest cover and physicochemical quality and biotic integrity indices in extensive large scale datasets. Measurements of hydromorphological conditions and riparian forest cover across different buffer widths for 59 × 103 river stretches covering 230 × 103 km of the French river network were coupled with data for physicochemical and biotic variables taken from the national monitoring network. General linear and quantile regression techniques were used to determine responses of physicochemical variables and biological integrity indices for macroinvertebrates and fish to riparian forest cover in selections of intermediate stress for 2nd to 4th order streams. Significant responses to forest cover were found for the nutrient variables and biological indices. According to these responses a 60% riparian forest cover in the 10 m buffer corresponds to good status boundaries for physicochemical and biotic elements. For the 30 m buffer, the observed response suggests that riparian forest coverage of at least 45% corresponds with good ecological status in the aquatic ecosystem. The observed consistent responses indicate significant potential for improving the quality of the aquatic environment by restoring riparian forest. The effects are more substantial in single-stressor environments but remain significant in multi-stressor environments.

  9. Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

    Science.gov (United States)

    Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

    2013-05-01

    Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs.

  10. Technology-Supported Inquiry for Learning about Aquatic Ecosystems

    Science.gov (United States)

    Hmelo-Silver, Cindy E.; Eberbach, Catherine; Jordan, Rebecca

    2014-01-01

    Understanding ecosystems is challenging, but important for becoming environmentally-literate citizens of today's society. People have difficulty considering how different components, mechanisms, and phenomena, both visible and invisible, are interconnected within ecosystems. This research presents both the design and initial testing of an…

  11. Response of shallow aquatic ecosystems to different nutrient loading levels.

    NARCIS (Netherlands)

    Portielje, R.

    1994-01-01

    Eutrophication of surface waters leads to a decline of water quality, which becomes manifest as an impoverishment of the aquatic community. Insight into the effects of eutrophication on the structure and functioning of these communities and knowlegde on underlying interactions is needed to quant

  12. Spatial variation of atmospheric nitrogen deposition and critical loads for aquatic ecosystems in the Greater Yellowstone Area.

    Science.gov (United States)

    Nanus, L; McMurray, J A; Clow, D W; Saros, J E; Blett, T; Gurdak, J J

    2017-04-01

    Current and historic atmospheric nitrogen (N) deposition has impacted aquatic ecosystems in the Greater Yellowstone Area (GYA). Understanding the spatial variation in total atmospheric deposition (wet + dry) of N is needed to estimate air pollution deposition critical loads for sensitive aquatic ecosystems. This is particularly important for areas that have an increasing contribution of ammonia dry deposition to total N (TN), such as the GYA. High resolution geostatistical models and maps of TN deposition (wet + dry) were developed using a variety of techniques including ordinary kriging in a geographic information system, to evaluate spatial variability and identify areas of elevated loading of pollutants for the GYA. TN deposition estimates in the GYA range from <1.4 to 7.5 kg N ha(-1) yr(-1) and show greater variability than wet inorganic N deposition. Critical loads of TN deposition (CLTNdep) for nutrient enrichment in aquatic ecosystems range from less than 1.5 ± 1.0 kg N ha(-1) yr(-1) to over 4.0 ± 1.0 kg N ha(-1) yr(-1) and variability is controlled by differences in basin characteristics. The lowest CLTNdep estimates occurred in high elevation basins within GYA Wilderness boundaries. TN deposition maps were used to identify critical load exceedances for aquatic ecosystems. Estimated CLTNdep exceedances for the GYA range from 17% to 48% depending on the surface water nitrate (NO3(-)) threshold. Based on a NO3(-) threshold of 1.0 μmol L(-1), TN deposition exceeds CLTNdep in approximately 30% of the GYA. These predictive models and maps can be used to help identify and protect sensitive ecosystems that may be impacted by excess atmospheric N deposition.

  13. Testing a 'genes-to-ecosystems' approach to understanding aquatic-terrestrial linkages.

    Science.gov (United States)

    Crutsinger, Gregory M; Rudman, Seth M; Rodriguez-Cabal, Mariano A; McKown, Athena D; Sato, Takuya; MacDonald, Andrew M; Heavyside, Julian; Geraldes, Armando; Hart, Edmund M; LeRoy, Carri J; El-Sabaawi, Rana W

    2014-12-01

    A 'genes-to-ecosystems' approach has been proposed as a novel avenue for integrating the consequences of intraspecific genetic variation with the underlying genetic architecture of a species to shed light on the relationships among hierarchies of ecological organization (genes → individuals → communities → ecosystems). However, attempts to identify genes with major effect on the structure of communities and/or ecosystem processes have been limited and a comprehensive test of this approach has yet to emerge. Here, we present an interdisciplinary field study that integrated a common garden containing different genotypes of a dominant, riparian tree, Populus trichocarpa, and aquatic mesocosms to determine how intraspecific variation in leaf litter alters both terrestrial and aquatic communities and ecosystem functioning. Moreover, we incorporate data from extensive trait screening and genome-wide association studies estimating the heritability and genes associated with litter characteristics. We found that tree genotypes varied considerably in the quality and production of leaf litter, which contributed to variation in phytoplankton abundances, as well as nutrient dynamics and light availability in aquatic mesocosms. These 'after-life' effects of litter from different genotypes were comparable to the responses of terrestrial communities associated with the living foliage. We found that multiple litter traits corresponding with aquatic community and ecosystem responses differed in their heritability. Moreover, the underlying genetic architecture of these traits was complex, and many genes contributed only a small proportion to phenotypic variation. Our results provide further evidence that genetic variation is a key component of aquatic-terrestrial linkages, but challenge the ability to predict community or ecosystem responses based on the actions of one or a few genes.

  14. Fire and aquatic ecosystems in forested biomes of North America

    Science.gov (United States)

    Gresswell, Robert E.

    1999-01-01

    Synthesis of the literature suggests that physical, chemical, and biological elements of a watershed interact with long-term climate to influence fire regime, and that these factors, in concordance with the postfire vegetation mosaic, combine with local-scale weather to govern the trajectory and magnitude of change following a fire event. Perturbation associated with hydrological processes is probably the primary factor influencing postfire persistence of fishes, benthic macroinvertebrates, and diatoms in fluvial systems. It is apparent that salmonids have evolved strategies to survive perturbations occurring at the frequency of wildland fires (100a??102 years), but local populations of a species may be more ephemeral. Habitat alteration probably has the greatest impact on individual organisms and local populations that are the least mobile, and reinvasion will be most rapid by aquatic organisms with high mobility. It is becoming increasingly apparent that during the past century fire suppression has altered fire regimes in some vegetation types, and consequently, the probability of large stand-replacing fires has increased in those areas. Current evidence suggests, however, that even in the case of extensive high-severity fires, local extirpation of fishes is patchy, and recolonization is rapid. Lasting detrimental effects on fish populations have been limited to areas where native populations have declined and become increasingly isolated because of anthropogenic activities. A strategy of protecting robust aquatic communities and restoring aquatic habitat structure and life history complexity in degraded areas may be the most effective means for insuring the persistence of native biota where the probability of large-scale fires has increased.

  15. Bioassay for aquatic ecosystems review and classification; Rassegna dei principali test di ecotossicologia acquatica

    Energy Technology Data Exchange (ETDEWEB)

    Sanci, Antonella; Rosa, Silvia [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1997-09-01

    Bioassay play a crucial role in assessing the actual or potential impacts of anthropogenic agents on the natural environment. In this technical report, literature on bioassays for aquatic ecosystems has been reviewed and classified. Problems associated with the choice and application of bioassays are discussed.

  16. Evaluation of nutrient limitation in aquatic ecosystems with nitrogen fixing bacteria

    Institute of Scientific and Technical Information of China (English)

    WU Gen-fu; WU Xue-chang; XUAN Xiao-dong; ZHOU Xue-ping

    2006-01-01

    There has always been a great need for simple and accurate bioassays for evaluating nutrient limitation in aquatic ecosystems. Whereas organic carbon is usually considered to be the limiting nutrient for microbial growth in many aquatic ecosystems,there are, however, many water sources that are limited by phosphorus or nitrogen. A method named "nitrogen fixing bacterial growth potential" (NFBGP) test, which is based on pre-culturing ofautochthonous (target) microorganisms was described. The method was applied to evaluate phosphorus or nitrogen nutrient limitation in lake and sewage water samples using an isolate of the nitrogen fixing bacterium, Azorhizobium sp. WS6. The results corresponded well to those from the traditional algal growth potential (AGP) test and the bacterial regrowth potential (BRP) test, suggesting that the NFBGP test is a useful supplementary method for evaluating the limiting nutrient, especially phosphorus, in an aquatic environment.

  17. Fundamental study on magnetic separation of aquatic organisms for preservation of marine ecosystem

    Science.gov (United States)

    Sakaguchi, F.; Akiyama, Y.; Izumi, Y.; Nishijima, S.

    2009-10-01

    Recently, destruction and disturbance of marine ecosystem have been caused by changes in global environment and transplants of farmed fishes and shellfishes. To solve the problems, water treatment techniques to kill or to remove aquatic organisms are necessary. In this study, application of magnetic separation for removal of the aquatic organisms was examined in order to establish the process with high-speed, compact device and low environmental load. Techniques of magnetic seeding and magnetic separation using superconducting magnet are important for high-speed processing of aquatic organisms. Magnetic seeding is to adhere separating object to the surface of ferromagnetic particles, and magnetic separation is to remove aquatic organisms with magnetic force. First, we confirmed the possibility of magnetic seeding of aquatic organisms, and then interaction between aquatic organisms and ferromagnetic particles was examined. Next, for practical application of magnetic separation system using superconducting magnet for removal of aquatic organisms, particle trajectories were simulated and magnetic separation experiment using superconducting magnet was performed in order to design magnetic separation system to achieve high separation efficiency.

  18. Interfaces in aquatic ecosystems: Implications for transport and impact of anthropogenic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Knulst, J.

    1996-11-01

    Mechanisms that govern transport, accumulation and toxicity of persistent pollutants at interfaces in aquatic ecosystems were the foci of this thesis. Specific attention was paid to humic substances, their occurrence, composition, and role in exchange processes across interfaces. It was concluded that: The composition of humic substances in aquatic surface microlayers is different from that of the subsurface water and terrestrial humic matter. Levels of dissolved organic carbon (DOC) in the aquatic surface microlayer reflect the DOC levels in the subsurface water. While the levels and enrichment of DOC in the microlayer generally show small variations, the levels and enrichment of particulate organic carbon (POC) vary to a great extent. Similarities exist between aquatic surface films, artificial semi-permeable and biological membranes regarding their structure and functioning. Acidification and liming of freshwater ecosystems affect DOC:POC ratio and humic composition of the surface film, thus influencing the partitioning of pollutants across aquatic interfaces. Properties of lake catchment areas extensively govern DOC:POC ratio both in the surface film and subsurface water. Increased UV-B irradiation changes the DOC:POC ratio in the surface film and thus affect transfer of matter across the interface. Transport of lipophilic, persistent organic pollutants across semi-permeable membranes is influenced by the solutes organic composition. 106 refs, 11 figs, 1 tab

  19. Managing aquatic ecosystems and water resources under multiple stress--an introduction to the MARS project.

    Science.gov (United States)

    Hering, Daniel; Carvalho, Laurence; Argillier, Christine; Beklioglu, Meryem; Borja, Angel; Cardoso, Ana Cristina; Duel, Harm; Ferreira, Teresa; Globevnik, Lidija; Hanganu, Jenica; Hellsten, Seppo; Jeppesen, Erik; Kodeš, Vit; Solheim, Anne Lyche; Nõges, Tiina; Ormerod, Steve; Panagopoulos, Yiannis; Schmutz, Stefan; Venohr, Markus; Birk, Sebastian

    2015-01-15

    Water resources globally are affected by a complex mixture of stressors resulting from a range of drivers, including urban and agricultural land use, hydropower generation and climate change. Understanding how stressors interfere and impact upon ecological status and ecosystem services is essential for developing effective River Basin Management Plans and shaping future environmental policy. This paper details the nature of these problems for Europe's water resources and the need to find solutions at a range of spatial scales. In terms of the latter, we describe the aims and approaches of the EU-funded project MARS (Managing Aquatic ecosystems and water Resources under multiple Stress) and the conceptual and analytical framework that it is adopting to provide this knowledge, understanding and tools needed to address multiple stressors. MARS is operating at three scales: At the water body scale, the mechanistic understanding of stressor interactions and their impact upon water resources, ecological status and ecosystem services will be examined through multi-factorial experiments and the analysis of long time-series. At the river basin scale, modelling and empirical approaches will be adopted to characterise relationships between multiple stressors and ecological responses, functions, services and water resources. The effects of future land use and mitigation scenarios in 16 European river basins will be assessed. At the European scale, large-scale spatial analysis will be carried out to identify the relationships amongst stress intensity, ecological status and service provision, with a special focus on large transboundary rivers, lakes and fish. The project will support managers and policy makers in the practical implementation of the Water Framework Directive (WFD), of related legislation and of the Blueprint to Safeguard Europe's Water Resources by advising the 3rd River Basin Management Planning cycle, the revision of the WFD and by developing new tools for

  20. Modeling an aquatic ecosystem: application of an evolutionary algorithm with genetic doping to reduce prediction uncertainty

    Science.gov (United States)

    Friedel, Michael; Buscema, Massimo

    2016-04-01

    Aquatic ecosystem models can potentially be used to understand the influence of stresses on catchment resource quality. Given that catchment responses are functions of natural and anthropogenic stresses reflected in sparse and spatiotemporal biological, physical, and chemical measurements, an ecosystem is difficult to model using statistical or numerical methods. We propose an artificial adaptive systems approach to model ecosystems. First, an unsupervised machine-learning (ML) network is trained using the set of available sparse and disparate data variables. Second, an evolutionary algorithm with genetic doping is applied to reduce the number of ecosystem variables to an optimal set. Third, the optimal set of ecosystem variables is used to retrain the ML network. Fourth, a stochastic cross-validation approach is applied to quantify and compare the nonlinear uncertainty in selected predictions of the original and reduced models. Results are presented for aquatic ecosystems (tens of thousands of square kilometers) undergoing landscape change in the USA: Upper Illinois River Basin and Central Colorado Assessment Project Area, and Southland region, NZ.

  1. Phosphate oxygen isotopes within aquatic ecosystems: Global data synthesis and future research priorities

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Ceri L. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Surridge, Ben W.J., E-mail: b.surridge@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Gooddy, Daren C. [British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB (United Kingdom)

    2014-10-15

    The oxygen isotope ratio of dissolved inorganic phosphate (δ{sup 18}O{sub p}) represents a novel and potentially powerful stable isotope tracer for biogeochemical research. Analysis of δ{sup 18}O{sub p} may offer new insights into the relative importance of different sources of phosphorus within natural ecosystems. Due to the isotope fractionations that occur alongside the metabolism of phosphorus, δ{sup 18}O{sub p} could also be used to better understand the intracellular and extracellular reaction mechanisms that control phosphorus cycling. In this review focussed on aquatic ecosystems, we examine the theoretical basis to using stable oxygen isotopes within phosphorus research. We consider the methodological challenges involved in accurately determining δ{sup 18}O{sub p}, given aquatic matrices in which potential sources of contaminant oxygen are ubiquitous. Finally, we synthesise the existing global data regarding δ{sup 18}O{sub p} in aquatic ecosystems, concluding by identifying four key areas for future development of δ{sup 18}O{sub p} research. Through this synthesis, we seek to stimulate broader interest in the use of δ{sup 18}O{sub p} to address the significant research and management challenges that continue to surround the stewardship of phosphorus. - Highlights: • Oxygen isotope ratio in dissolved inorganic phosphate a novel stable isotope tracer. • Theoretical basis for application of this tracer in aquatic ecosystems reviewed. • Protocols for determining phosphate oxygen isotope ratio summarised. • Synthesis of global data from marine and freshwater ecosystems reported. • Priorities for future research in this rapidly evolving field identified.

  2. Heavy metal pollution characteristics of surface sediments in different aquatic ecosystems in eastern China: a comprehensive understanding.

    Directory of Open Access Journals (Sweden)

    Wenzhong Tang

    Full Text Available Aquatic ecosystems in eastern China are suffering threats from heavy metal pollution because of rapid economic development and urbanization. Heavy metals in surface sediments were determined in five different aquatic ecosystems (river, reservoir, estuary, lake, and wetland ecosystems. The average Cd, Cr, Cu, Ni, Pb, and Zn concentrations were 0.716, 118, 37.3, 32.7, 56.6, and 204 mg/kg, respectively, and the higher concentrations were mainly found in sediment samples from river ecosystems. Cd was the most anthropogenically enriched pollutant, followed by Zn and Pb, indicated by enrichment factors >1.5. According to consensus-based sediment quality guidelines, potential ecological risk indices, and risk assessment codes, all five types of aquatic ecosystems were found to be polluted with heavy metals, and the most polluted ecosystems were mainly rivers. Cd was the most serious pollutant in all five aquatic ecosystems, and it was mainly found in the exchangeable fraction (about 30% of the total Cd concentration, on average. The results indicate that heavy metal contamination, especially of Cd, in aquatic ecosystems in eastern China should be taken into account in the development of management strategies for protecting the aquatic environment.

  3. Drought sensitivity predicts habitat size sensitivity in an aquatic ecosystem.

    Science.gov (United States)

    Amundrud, Sarah L; Srivastava, Diane S

    2015-07-01

    Species and trophic richness often increase with habitat size. Although many ecological processes have been evoked to explain both patterns, the environmental stress associated with small habitats has rarely been considered. We propose that larger habitats may be species rich simply because their environmental conditions are within the fundamental niche of more species; larger habitats may also have more trophic levels if traits of predators render them vulnerable to environmental stress. We test this hypothesis using the aquatic insect larvae in water-filled bromeliads. In bromeliads, the probability of desiccation is greatest in small plants. For the 10 most common bromeliad insect taxa, we ask whether differences in drought tolerance and regional abundances between taxa predict community and trophic composition over a gradient of bromeliad size. First, we used bromeliad survey data to calculate the mean habitat size of occurrence of each taxon. Comparing the observed mean habitat size of occurrence to that expected from random species assembly based on differences in their regional abundances allowed us to obtain habitat size sensitivity indices (as Z scores) for the various insect taxa. Second, we obtained drought sensitivity indices by subjecting individual insects to drought and measuring the effects on relative growth rates in a mesocosm experiment. We found that drought sensitivity strongly, predicts habitat size sensitivity in bromeliad insects. However, an increase in trophic richness with habitat size could not be explained by an increased sensitivity of predators to drought, but rather by sampling effects, as predators were rare compared to lower trophic levels. This finding suggests that physiological tolerance to environmental stress can be relevant in explaining the universal increase in species with habitat size.

  4. Transport and fate of radionuclides in aquatic environments--the use of ecosystem modelling for exposure assessments of nuclear facilities.

    Science.gov (United States)

    Kumblad, L; Kautsky, U; Naeslund, B

    2006-01-01

    In safety assessments of nuclear facilities, a wide range of radioactive isotopes and their potential hazard to a large assortment of organisms and ecosystem types over long time scales need to be considered. Models used for these purposes have typically employed approaches based on generic reference organisms, stylised environments and transfer functions for biological uptake exclusively based on bioconcentration factors (BCFs). These models are of non-mechanistic nature and involve no understanding of uptake and transport processes in the environment, which is a severe limitation when assessing real ecosystems. In this paper, ecosystem models are suggested as a method to include site-specific data and to facilitate the modelling of dynamic systems. An aquatic ecosystem model for the environmental transport of radionuclides is presented and discussed. With this model, driven and constrained by site-specific carbon dynamics and three radionuclide specific mechanisms: (i) radionuclide uptake by plants, (ii) excretion by animals, and (iii) adsorption to organic surfaces, it was possible to estimate the radionuclide concentrations in all components of the modelled ecosystem with only two radionuclide specific input parameters (BCF for plants and Kd). The importance of radionuclide specific mechanisms for the exposure to organisms was examined, and probabilistic and sensitivity analyses to assess the uncertainties related to ecosystem input parameters were performed. Verification of the model suggests that this model produces analogous results to empirically derived data for more than 20 different radionuclides.

  5. Staunton 1 reclamation demonstration project. Aquatic ecosystems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinikour, W. S.

    1981-02-01

    To provide long-term indications of the potential water quality improvements following reclamation efforts at the Staunton 1 Reclamation Demonstration Project, macroinvertebrates were collected from three on-site ponds and from the receiving stream (Cahokia Creek) for site drainage. Implications for potential benthic community differences resulting from site runoff were disclosed, but macroinvertebrate diversity throughout Cahokia Creek was limited due to an unstable, sandy substrate. The three ponds sampled were the New Pond, which was created as part of the reclamation activities; the Shed Pond, which and the Old Pond, which, because it was an existing, nonimpacted pond free of site runoff, served as a control. Comparisons of macroinvertebrates from the ponds indicated the potential for the New Pond to develop into a productive ecosystem. Macroinvertebrates in the New Pond were generally species more tolerant of acid mine drainage conditions. However, due to the present limited faunal densities and the undesirable physical and chemical characteristics of the New Pond, the pond should not be stocked with fish at this time.

  6. Metallic Pollution of Aquatic Ecosystems: Water of OumerRbiariver

    Directory of Open Access Journals (Sweden)

    Y. Asfers

    2016-09-01

    Full Text Available This study comes after a series of studies evaluating the quality of OumEr-Rbia river(1-4, the choice of this ecosystem is determined by the socioeconomic importance of this river and the high pollutant caused by the agglomeration and industrial units distributed through the banks and tributaries. Their rejects in the watercourses of OumEr-Rbia can modify the quality of the water and prevent the development of socioeconomic activities. In our study we have focused to evaluate the contamination degree by toxic metals Zn, Co,Cr, Al by the mesure of their amount in different stations in two companions. The result show that the stations S4, S8 and S9 of OumEr-Rbiariver are contaminated by cobalt, then, in the S4, the manganese amount exceeds the Moroccan standard values in this metal intended for the irrigation. However, the measure of Cr Zn and Al show that are favorable for the irrigation

  7. Selenium biotransformations in an engineered aquatic ecosystem for bioremediation of agricultural wastewater via brine shrimp production.

    Science.gov (United States)

    Schmidt, Radomir; Tantoyotai, Prapakorn; Fakra, Sirine C; Marcus, Matthew A; Yang, Soo In; Pickering, Ingrid J; Bañuelos, Gary S; Hristova, Krassimira R; Freeman, John L

    2013-05-21

    An engineered aquatic ecosystem was specifically designed to bioremediate selenium (Se), occurring as oxidized inorganic selenate from hypersalinized agricultural drainage water while producing brine shrimp enriched in organic Se and omega-3 and omega-6 fatty acids for use in value added nutraceutical food supplements. Selenate was successfully bioremediated by microalgal metabolism into organic Se (seleno-amino acids) and partially removed via gaseous volatile Se formation. Furthermore, filter-feeding brine shrimp that accumulated this organic Se were removed by net harvest. Thriving in this engineered pond system, brine shrimp ( Artemia franciscana Kellogg) and brine fly (Ephydridae sp.) have major ecological relevance as important food sources for large populations of waterfowl, breeding, and migratory shore birds. This aquatic ecosystem was an ideal model for study because it mimics trophic interactions in a Se polluted wetland. Inorganic selenate in drainage water was metabolized differently in microalgae, bacteria, and diatoms where it was accumulated and reduced into various inorganic forms (selenite, selenide, or elemental Se) or partially incorporated into organic Se mainly as selenomethionine. Brine shrimp and brine fly larva then bioaccumulated Se from ingesting aquatic microorganisms and further metabolized Se predominately into organic Se forms. Importantly, adult brine flies, which hatched from aquatic larva, bioaccumulated the highest Se concentrations of all organisms tested.

  8. EcoCasting: Using NetLogo models of aquatic ecosystems to teach scientific inquiry

    Science.gov (United States)

    Buzby, C. K.; Jona, K.

    2010-12-01

    The EcoCasting project from the Office of STEM Education Partnerships (OSEP) at Northwestern University has developed a computer model-based curriculum for high school environmental science classes to study complexity in aquatic ecosystems. EcoCasting aims to deliver cutting edge scientific research on bioaccumulation in invaded Great Lakes food webs to high school classes. Scientists and environmental engineers at Northwestern are investigating unusual bioaccumulation patterns in invaded food webs of the Great Lakes. High school students are exploring this authentic data to understand what is causing the anomalies in the data. Students use a series of NetLogo agent-based models of an aquatic ecosystem to study how toxins accumulate in the food web. Using these models, students learn about predator-prey relationships, bioaccumulation, and invasive species. Students are confronted with contradictory data collected by scientists and investigate alternative food web mechanisms at work. By studying the individual variables, students learn common scientific principles. When multiple variables are combined in a unifying model, students learn that the interactions lead to unexpected outcomes. Students learn about the complexity of the ecosystem and gain proficiency interpreting computer models and scientific data collection in this curriculum. Model of aquatic food chain

  9. Aquatic Ecosystems, Water Quality, and Global Change: Challenges of Conducting Multi-Stressor Vulnerability Assessments (Final Report)

    Science.gov (United States)

    EPA announced the availability of the final report, Aquatic Ecosystems and Global Change: The Challenges of conducting Multi-Stressor Global Change Vulnerability Assessments. This report investigates the issues and challenges associated with identifying, calculating, and ...

  10. Field flume reveals aquatic vegetation's role in sediment and particulate phosphorus transport in a shallow aquatic ecosystem

    Science.gov (United States)

    Harvey, Judson W.; Noe, Gregory B.; Larsen, Laurel G.; Nowacki, Daniel J.; McPhillips, Lauren E.

    2011-03-01

    Flow interactions with aquatic vegetation and effects on sediment transport and nutrient redistribution are uncertain in shallow aquatic ecosystems. Here we quantified sediment transport in the Everglades by progressively increasing flow velocity in a field flume constructed around undisturbed bed sediment and emergent macrophytes. Suspended sediment 100 μm became dominant at higher velocity steps after a threshold shear stress for bed floc entrainment was exceeded. Shedding of vortices that had formed downstream of plant stems also occurred on that velocity step which promoted additional sediment detachment from epiphyton. Modeling determined that the potentially entrainable sediment reservoir, 46 g m - 2 , was similar to the reservoir of epiphyton (66 g m - 2 ) but smaller than the reservoir of flocculent bed sediment (330 g m - 2 ). All suspended sediment was enriched in phosphorus (by approximately twenty times) compared with bulk sediment on the bed surface and on plant stems, indicating that the most easily entrainable sediment is also the most nutrient rich (and likely the most biologically active).

  11. Atmospheric transport of persistent organic pollutants to aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Agrell, Cecilia

    1999-04-01

    The load of persistent organic pollutants (POPs) is considered high in the Baltic ecosystem. The Baltic Sea spans over 12 latitudes and the regional differences in climate affect the behavior of POPs. Therefore spatial and temporal variability of the concentrations of POPs in air and precipitation within this area has been investigated at 16 (mostly rural) stations around the Baltic Sea between 1990-1993. In addition, the deposition of gaseous and particulate associated POPs to the Baltic Sea is estimated from empirical data. This atmospheric input of POPs is compared with the input from rivers. Additionally, data from Ross Island, Antarctica and Lake Kariba, Zimbabve, Africa is presented, and all results are discussed and explained using the `global fractionation hypothesis` as a framework. In the Baltic Sea, concentration of individual POPs in air were found to be influenced by their physical-chemical properties, ambient air temperature and location. A latitudinal gradient, with higher levels in the south was found for PCBs and the gradient was more pronounced for the low volatility congeners. As a result, the high volatility congeners in air increased in relative importance with latitude. Generally, PCB concentration increased with temperature, but slopes of the partial pressure in air versus reciprocal temperature were different between congeners and between stations. In general, the low volatility congeners were more temperature dependent than the high volatility PCB congeners. Steep slopes at a sampling location indicate that the concentration in air is largely determined by diffusive exchange with soils. Lack of a temperature dependence may be due to the influence of long-range transported air masses at remote sites and due to the episodic, or random nature of PCB sources at urban sites. The concentrations of individual congeners in precipitation were found to be influenced by atmospheric concentrations of PCBs, ambient temperature, precipitation volume and

  12. The feasibility of automated online flow cytometry for in-situ monitoring of microbial dynamics in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Michael Domenic Besmer

    2014-06-01

    Full Text Available Fluorescent staining coupled with flow cytometry (FCM is often used for the monitoring, quantification and characterization of bacteria in engineered and environmental aquatic ecosystems including seawater, freshwater, drinking water, wastewater, and industrial bioreactors. However, infrequent grab sampling hampers accurate characterization and subsequent understanding of microbial dynamics in all of these ecosystems. A logic technological progression is high throughput and full automation of the sampling, staining, measurement, and data analysis steps. Here we assess the feasibility and applicability of automated FCM by means of actual data sets produced with prototype instrumentation. As proof-of-concept we demonstrate examples of microbial dynamics in (i flowing tap water from a municipal drinking water supply network and (ii river water from a small creek subject to two rainfall events. In both cases, automated measurements were done at 15-min intervals during 12 to 14 consecutive days, yielding more than 1000 individual data points for each ecosystem. The extensive data sets derived from the automated measurements allowed for the establishment of baseline data for each ecosystem, as well as for the recognition of daily variations and specific events that would most likely be missed (or miss-characterized by infrequent sampling. In addition, the online FCM data from the river water was combined and correlated with online measurements of abiotic parameters, showing considerable potential for a better understanding of cause-and-effect relationships in aquatic ecosystems. Although several challenges remain, the successful operation of an automated online FCM system and the basic interpretation of the resulting data sets represent a breakthrough towards the eventual establishment of fully automated online microbiological monitoring technologies.

  13. ELF Communications System Ecological Monitoring Program: Aquatic Ecosystem Studies.

    Science.gov (United States)

    1994-11-01

    Evenness 50 0.365 99 99 Achnanthes m-inutissima 47 0.605 99 92 relative abundance Cocconeis placentula 46 0.108 99 76 relative abundance -The...following were log (x+l) prior to BACI analysis: chlorophyll a standing crop, cell volume, biovolume; The following were arcsin irx transformed: Achnanthes ...reports included all data (winter and summer) and periods from June to October when diatom counts were dominated by Cocconeis placentula and Achnanthes

  14. Floods, fish, and people: Connecting biogeochemical fluxes to aquatic ecosystem functions and people (Invited)

    Science.gov (United States)

    Holtgrieve, G. W.; Arias, M. E.; Chheng, P.

    2013-12-01

    The Lower Mekong River basin, including Tonle Sap Lake (TSL), is the largest inland fishery in the world and a dominant source of protein and income for much of Southeast Asia. Maintaining ecosystem productivity in the face of large-scale environmental change from hydroelectric dams and climate change is critical for economic and social well-being in the region. Yet, we currently lack the most basic understanding of how hydrologic variation relates to fisheries production, nutritional quality, and ultimately livelihoods of people. We will describe past, present, and future research to establish mechanistic connections between the hydrology, ecology, and sustainability of the Mekong ecosystem. Past research includes application of a state-space oxygen mass balance model and continuous dissolved oxygen measurements from four locations to provide the first estimates of gross primary productivity (GPP) and ecosystem respiration (ER) for the Tonle Sap. GPP averaged 4.1 × 2.3 g O2 m-3 d-1 with minimal differences among sites, while ER averaged 24.9 × 20.0 g O2 m-3 d-1, but had greater than six-fold variation among sites. Using our measurements of GPP, we calibrated a hydrodynamic-productivity model and predicted aquatic net primary production of 2.0 × 0.2 g C m-2 d-1 (2.4 × 0.2 million tonnes C y-1). Present research is using stable isotope and fatty acid methyl ester biomarkers to investigate basal carbon sources to the fishery, focusing specifically on the role of biogenic methane oxidation in supporting the food web. Individuals a wide variety of taxa had tissue carbon isotope values (δ13C) ranging from -36 to -57 per mil. These extremely depleted values are best explained by utilization of biogenic methane by methane oxidizing bacteria (MOB) and subsequent grazing of these bacterial by benthic insects and ultimately fishes. The presence of MOB in the food web was confirmed by identifying 16:1ω8 and 18:1ω8 FAME biomarkers specific to these bacteria in fish

  15. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Science.gov (United States)

    Jones, Bobette E; Krupa, Monika; Tate, Kenneth W

    2013-01-01

    The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010) involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i) Phase 1 in January 2004, (ii) Phase 2 in August 2005, and (iii) Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S) showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management practices

  16. Aquatic ecosystem response to timber harvesting for the purpose of restoring aspen.

    Directory of Open Access Journals (Sweden)

    Bobette E Jones

    Full Text Available The removal of conifers through commercial timber harvesting has been successful in restoring aspen, however many aspen stands are located near streams, and there are concerns about potential aquatic ecosystem impairment. We examined the effects of management-scale conifer removal from aspen stands located adjacent to streams on water quality, solar radiation, canopy cover, temperature, aquatic macroinvertebrates, and soil moisture. This 8-year study (2003-2010 involved two projects located in Lassen National Forest. The Pine-Bogard Project consisted of three treatments adjacent to Pine and Bogard Creeks: (i Phase 1 in January 2004, (ii Phase 2 in August 2005, and (iii Phase 3 in January 2008. The Bailey Project consisted of one treatment adjacent to Bailey Creek in September 2006. Treatments involved whole tree removal using track-laying harvesters and rubber tire skidders. More than 80% of all samples analyzed for NO₃-N, NH₄-N, and PO₄-P at Pine, Bogard, and Bailey Creeks were below the detection limit, with the exception of naturally elevated PO₄-P in Bogard Creek. All nutrient concentrations (NO₃-N, NH₄-N, PO₄-P, K, and SO₄-S showed little variation within streams and across years. Turbidity and TSS exhibited annual variation, but there was no significant increase in the difference between upstream and downstream turbidity and TSS levels. There was a significant decrease in stream canopy cover and increase in the potential fraction of solar radiation reaching the streams in response to the Pine-Bogard Phase 3 and Bailey treatments; however, there was no corresponding increase in stream temperatures. Macroinvertebrate metrics indicated healthy aquatic ecosystem conditions throughout the course of the study. Lastly, the removal of vegetation significantly increased soil moisture in treated stands relative to untreated stands. These results indicate that, with careful planning and implementation of site-specific best management

  17. Water quality assessment of aquatic ecosystems using ecological criteria - case study in Bulgaria.

    Science.gov (United States)

    Damyanova, Sonya; Ivanova, Iliana; Ignatova, Nadka

    2014-11-02

    Four aquatic ecosystems (two rivers and two dams) situated in the western part of Bulgaria were investigated over a three years' period. The River Egulya and Petrohan dam are situated in mountainous regions at about 1000 m altitude, and are not influenced by any anthropogenic sources. Petrohan dam is a site for long-term ecosystem research as a part of Bulgarian long-term ecological research network. The other two systems belong to populated industrial areas. The River Martinovska flows through a region with former long-term mining activity, while Ogosta dam is near a battery production factory. Both the geochemical and geographical ecosystems' conditions are different, and their social usage as well. Ogosta dam water is used for irrigation and Petrohan dam for electric supply. The ecosystem sensitivity to heavy metals was evaluated by a critical load approach. Two criteria were used for risk assessment: critical load exceedance and microbial toxicity test. All studied ecosystems were more sensitive to cadmium than to lead deposition. The potential risk of Cd damage is higher for Petrohan dam and the River Egulya, where critical load exceedance was calculated for two years. Pseudomonas putida growth inhibition test detected a lack of toxicity for all studied ecosystems at the time of investigation with the exception of the low water September sample of the River Martinovska. The fast bacterial test is very suitable for a regular measurement of water toxicity because of its simplicity, lack of sophisticated equipment and clear results.

  18. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: an ecosustainable approach.

    Science.gov (United States)

    Rai, Prabhat Kumar

    2008-01-01

    This review addresses the global problem of heavymetal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. Heavymetal contamination in aquatic ecosystems due to discharge of industrial effluents may pose a serious threat to human health. Alkaline precipitation, ion exchange columns, electrochemical removal, filtration, and membrane technologies are the currently available technologies for heavy metal removal. These conventional technologies are not economical and may produce adverse impacts on aquatic ecosystems. Phytoremediation of metals is a cost-effective "green" technology based on the use of specially selected metal-accumulating plants to remove toxic metals from soils and water. Wetland plants are important tools for heavy metal removal. The Ramsar convention, one of the earlier modern global conservation treaties, was adopted at Ramsar, Iran, in 1971 and became effective in 1975. This convention emphasized the wise use of wetlands and their resources. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. The extensive rhizosphere of wetland plants provides an enriched culture zone for the microbes involved in degradation. The wetland sediment zone provides reducing conditions that are conducive to the metal removal pathway. Constructed wetlands proved to be effective for the abatement of heavymetal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some

  19. Heavy metal pollution in aquatic ecosystems and its phytoremediation using wetland plants: An ecosustainable approach

    Energy Technology Data Exchange (ETDEWEB)

    Rai, P.K. [Mizoram Central University, Tanhril (India). School for Earth Science & Natural Resource Management

    2008-07-01

    This review addresses the global problem of heavy metal pollution originating from increased industrialization and urbanization and its amelioration by using wetland plants both in a microcosm as well as natural/field condition. This review mentions salient features of wetland ecosystems, their vegetation component, and the pros and cons involved in heavy metal removal. Wetland plants are preferred over other bio-agents due to their low cost, frequent abundance in aquatic ecosystems, and easy handling. Constructed wetlands proved to be effective for the abatement of heavy metal pollution from acid mine drainage; landfill leachate; thermal power; and municipal, agricultural, refinery, and chlor-alkali effluent. the physicochemical properties of wetlands provide many positive attributes for remediating heavy metals. Typha, Phragmites, Eichhornia, Azolla, Lemna, and other aquatic macrophytes are some of the potent wetland plants for heavy metal removal. Biomass disposal problem and seasonal growth of aquatic macrophytes are some limitations in the transfer of phytoremediation technology from the laboratory to the field. However, the disposed biomass of macrophytes may be used for various fruitful applications. An ecosustainable model has been developed through the author's various works, which may ameliorate some of the limitations. The creation of more areas for phytoremediation may also aid in wetlands conservation. Genetic engineering and biodiversity prospecting of endangered wetland plants are important future prospects in this regard.

  20. Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining

    Science.gov (United States)

    Schmidt, T.S.; Church, S.E.; Clements, W.H.; Mitchell, K.A.; Fey, D. L.; Wanty, R.B.; Verplanck, P.L.; San, Juan C.A.; Klein, T.L.; deWitt, E.H.; Rockwell, B.W.

    2009-01-01

    Stream water and sediment toxicity to aquatic insects were quantified from central Colorado catchments to distinguish the effect of geologic processes which result in high background metals concentrations from historical mining. Our sampling design targeted small catchments underlain by rocks of a single lithology, which allowed the development of biological and geochemical baselines without the complication of multiple rock types exposed in the catchment. By accounting for geologic sources of metals to the environment, we were able to distinguish between the environmental effects caused by mining and the weathering of different mineralized areas. Elevated metal concentrations in water and sediment were not restricted to mined catchments. Impairment of aquatic communities also occurred in unmined catchments influenced by hydrothermal alteration. Hydrothermal alteration style, deposit type, and mining were important determinants of water and sediment quality and aquatic community structure. Weathering of unmined porphyry Cu-Mo occurrences resulted in water (median toxic unit (TU) = 108) and sediment quality (TU = 1.9) that exceeded concentrations thought to be safe for aquatic ecosystems (TU = 1). Metalsensitive aquatic insects were virtually absent from streams draining catchments with porphyry Cu-Mo occurrences (1.1 individuals/0.1 m2 ). However, water and sediment quality (TU = 0.1, 0.5 water and sediment, respectively) and presence of metalsensitive aquatic insects (204 individuals/0.1 m2 ) for unmined polymetallic vein occurrences were indistinguishable from that for unmined and unaltered streams (TU = 0.1, 0.5 water and sediment, respectively; 201 individuals/0.1 m2 ). In catchments with mined quartz-sericite-pyrite altered polymetallic vein deposits, water (TU = 8.4) and sediment quality (TU = 3.1) were degraded and more toxic to aquatic insects (36 individuals/0.1 m2 ) than water (TU = 0.4) and sediment quality (TU = 1.7) from mined propylitically altered

  1. Impacts on Tocantins River aquatic ecosystems resulting from the development of the hydropower potential

    Directory of Open Access Journals (Sweden)

    Jorge Machado Damasio

    2010-04-01

    Full Text Available Regardless the obvious success of using hydropower plants to supply energy for economic development, they may result in several environmental and social impacts with different levels of severity on the aquatic ecosystems and on the human communities living in the region. The objective of this study was to identify environmental problems and impacts to the aquatic ecosystems in Tocantins river related to the development of its hydropower potential and contribute to the target of balancing of energy generation with biodiversity and genetic flux preservation. The scenario considered the hydropower plants Peixe Angical and São Salvador. The Causal Chain Analysis (CCA was used to identify the environmental impacts and their immediate, sectarian and root causes. The impacts were ranked according to the characterization matrix, having the fish communities as the main indicators. The most relevant impacts were: (i degradation of water resources, (ii loss and changes in habitats, (iii changes in the ecosystems stability, (iv reduction of fish stocks, (v interference with benthic communities and microorganism’s populations, (vi changes in the food-chain and (vii interference with the dispersion of fishes and mammals.

  2. An explicit GIS-based river basin framework for aquatic ecosystem conservation in the Amazon

    Science.gov (United States)

    Venticinque, Eduardo; Forsberg, Bruce; Barthem, Ronaldo; Petry, Paulo; Hess, Laura; Mercado, Armando; Cañas, Carlos; Montoya, Mariana; Durigan, Carlos; Goulding, Michael

    2016-11-01

    Despite large-scale infrastructure development, deforestation, mining and petroleum exploration in the Amazon Basin, relatively little attention has been paid to the management scale required for the protection of wetlands, fisheries and other aspects of aquatic ecosystems. This is due, in part, to the enormous size, multinational composition and interconnected nature of the Amazon River system, as well as to the absence of an adequate spatial model for integrating data across the entire Amazon Basin. In this data article we present a spatially uniform multi-scale GIS framework that was developed especially for the analysis, management and monitoring of various aspects of aquatic systems in the Amazon Basin. The Amazon GIS-Based River Basin Framework is accessible as an ESRI geodatabase at doi:10.5063/F1BG2KX8.

  3. Water quality assessment of aquatic ecosystems using ecological criteria – case study in Bulgaria

    Science.gov (United States)

    Damyanova, Sonya; Ivanova, Iliana; Ignatova, Nadka

    2014-01-01

    Four aquatic ecosystems (two rivers and two dams) situated in the western part of Bulgaria were investigated over a three years’ period. The River Egulya and Petrohan dam are situated in mountainous regions at about 1000 m altitude, and are not influenced by any anthropogenic sources. Petrohan dam is a site for long-term ecosystem research as a part of Bulgarian long-term ecological research network. The other two systems belong to populated industrial areas. The River Martinovska flows through a region with former long-term mining activity, while Ogosta dam is near a battery production factory. Both the geochemical and geographical ecosystems’ conditions are different, and their social usage as well. Ogosta dam water is used for irrigation and Petrohan dam for electric supply. The ecosystem sensitivity to heavy metals was evaluated by a critical load approach. Two criteria were used for risk assessment: critical load exceedance and microbial toxicity test. All studied ecosystems were more sensitive to cadmium than to lead deposition. The potential risk of Cd damage is higher for Petrohan dam and the River Egulya, where critical load exceedance was calculated for two years. Pseudomonas putida growth inhibition test detected a lack of toxicity for all studied ecosystems at the time of investigation with the exception of the low water September sample of the River Martinovska. The fast bacterial test is very suitable for a regular measurement of water toxicity because of its simplicity, lack of sophisticated equipment and clear results. PMID:26019591

  4. Nutritional composition of aquatic species in Laotian rice field ecosystems : possible impact of reduced biodiversity

    OpenAIRE

    Nurhasan, Mulia

    2008-01-01

    The population density of Laos PDR has increased from 15 persons per square km in 1985 to 19 persons in 1995 and to 24 persons in 2005. This has threatened food security, which in Laos PDR is generally synonymous with rice availability. Rice production in Laos rose by 70 percent from 1990 to 2004. Evidence from Vietnam, Malaysia and Central Thailand has shown that the rise of rice production steadily decreases the population of aquatic animals in rice field ecosystems, as a result of higher a...

  5. Global meta-analysis of native and nonindigenous trophic traits in aquatic ecosystems.

    Science.gov (United States)

    McKnight, Ella; García-Berthou, Emili; Srean, Pao; Rius, Marc

    2016-10-26

    Ecologists have recently devoted their attention to the study of species traits and their role in the establishment and spread of nonindigenous species (NIS). However, research efforts have mostly focused on studies of terrestrial taxa, with lesser attention being dedicated to aquatic species. Aquatic habitats comprise of interconnected waterways, as well as exclusive introduction vectors that allow unparalleled artificial transport of species and their propagules. Consequently, species traits that commonly facilitate biological invasions in terrestrial systems may not be as represented in aquatic environments. We provide a global meta-analysis of studies conducted in both marine and freshwater habitats. We selected studies that conducted experiments with native and NIS under common environmental conditions to allow detailed comparisons among species traits. In addition, we explored whether different factors such as species relatedness, functional feeding groups, latitude, climate, and experimental conditions could be linked to predictive traits. Our results show that species with traits that enhance consumption and growth have a substantially increased probability of establishing and spreading when entering novel ecosystems. Moreover, traits associated with predatory avoidance were more prevalent in NIS and therefore favour invasive species in aquatic habitats. When we analysed NIS interacting with taxonomically distinctive native taxa, we found that consumption and growth were particularly important traits. This suggests that particular attention should be paid to newly introduced species for which there are no close relatives in the local biota. Finally, we found a bias towards studies conducted in temperate regions, and thus, more studies in other climatic regions are needed. We conclude that studies aiming at predicting future range shifts should consider trophic traits of aquatic NIS as these traits are indicative of multiple interacting mechanisms involved

  6. Advances in management and utilization of invasive water hyacinth (Eichhornia crassipes) in aquatic ecosystems - a review.

    Science.gov (United States)

    Yan, Shao-Hua; Song, Wei; Guo, Jun-Yao

    2017-03-01

    The objective of this review is to provide a concise summary of literature in the Chinese language since late 1970s and focuses on recent development in global scenarios. This work will replenish the FAO summary of water hyacinth utilization from 1917 to 1979 and review ecological and socioeconomic impacts of the water hyacinth from 1980 to 2010. This review also discusses the debate on whether the growth of the water hyacinth is a problem, a challenge or an opportunity. Literature suggested that integrated technologies and good management may be an effective solution and the perception of water hyacinth could change from that of a notorious aquatic weed to a valuable resource, including its utilization as a biological agent for the application in bioremediation for removing excess nutrients from eutrophic water bodies at low cost. Key aspects on system integration and innovation may focus on low-cost and efficient equipment and the creation of value-added goods from water hyacinth biomass. In the socioeconomic and ecological domain of global development, all the successful and sustainable management inputs for the water hyacinth must generate some sort of social and economic benefit simultaneously, as well as benefiting the ecosystem. Potential challenges exist in linkages between the management of water hyacinth on the large scale to the sustainable development of agriculture based on recycling nutrients, bio-energy production or silage and feed production. Further research and development may focus on more detailed biology of water hyacinth related with its utilization, cost-benefit analysis of middle to large-scale application of the technologies and innovation of the equipment used for harvesting and dehydrating the plant.

  7. Interaction of acid rain and global changes: effects on terrestrial and aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R.F.; Schindler, D.W. [Norwegian Institute for Water Research, Oslo (Norway)

    1995-12-01

    Both acid deposition and changes in the global atmosphere and climate affect terrestrial and aquatic ecosystems. In the atmosphere sulphate aerosols tend to increase haze, altering the global radiation balance. Increased nitrogen deposition to N-limited systems such as boreal forests results in increased growth and increased sequestration of atmospheric CO{sub 2}, slowing the increase in CO{sub 2} levels in the atmosphere. Future reduction in S and N emissions may results in a trade-off better with respect to some effects of acid deposition and greenhouse warming, but worse with respect to others. Global warming may cause the incidence and severity of drought to increase. Mineralisation of N and oxidation of organic S compounds release pulses of SO{sub 4}, acid and Al to surface waters. Effects in lakes may include reduced deep water refugia for cold stenotherms, lower nutrient concentrations, and greater penetration of harmful UV radiation. Longer water renewal times cause declines in SO{sub 4} and NO{sub 3} due to increased in situ removal, but increases in base cations. The net result in increased internal alkalinity production. In areas characterised by cold winters, global warming may result in a major shift in hydrologic cycle, with snowmelt episodes occurring during the winter rather than the typical pattern of accumulation in the winter and melting in the spring. Increased storm frequency predicted for the future will cause increased frequency and severity of sea salt episodes in coastal regions. Predicting the interactions of regional and global environmental factors in the coming decades poses new challenges to scientists, managers and policy-makers. 52 refs., 5 figs.

  8. Interaction of acid rain and global changes: Effects on terrestrial and aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R.F. [Norsk Inst. for Vannforskning, Oslo (Norway); Schindler, D.W.

    1995-07-01

    Both acid deposition and changes in the global atmosphere and climate affect terrestrial and aquatic ecosystems. In the atmosphere sulphate aerosols tend to increase haze, altering the global radiation balance. Increased nitrogen deposition to N-limited systems such as boreal forests results in increased growth and increased sequestration of atmospheric CO{sub 2} slowing the increase in CO{sub 2} levels in the atmosphere. Future reduction in S and N emissions may result in trade-off -- better with respect to some effects of acid deposition and greenhouse warming but worse with respect to others. Global warming may cause the incidence and severity of drought to increase. Mineralisation of N and oxidation of organic S compounds release pulses of SO{sub 4}, acid and Al to surface waters. Effect in lakes may include reduced deep water refugia for cold stenotherms, lower nutrient concentration and greater penetration of harmful UV radiation. Longer water renewal times cause declines in SO{sub 4} and NO{sub 3} due to increased in situ removal but increases in base cations. The net result is increased internal alkalinity production. In areas characterised by cold winters, global warming may result in major shift in hydrologic cycle, with snow melt episodes occurring during the winter rather than the typical pattern of accumulation in the winter and melting in the spring. Increased storm frequency predicted for the future will cause increased frequency and severity of sea salt episodes in coastal regions. Predicting the interactions of regional and global environmental factors in the coming decades poses new challenges to scientists, managers and policy makers.

  9. Adaptive genetic variation mediates bottom-up and top-down control in an aquatic ecosystem

    Science.gov (United States)

    Rudman, Seth M.; Rodriguez-Cabal, Mariano A.; Stier, Adrian; Sato, Takuya; Heavyside, Julian; El-Sabaawi, Rana W.; Crutsinger, Gregory M.

    2015-01-01

    Research in eco-evolutionary dynamics and community genetics has demonstrated that variation within a species can have strong impacts on associated communities and ecosystem processes. Yet, these studies have centred around individual focal species and at single trophic levels, ignoring the role of phenotypic variation in multiple taxa within an ecosystem. Given the ubiquitous nature of local adaptation, and thus intraspecific variation, we sought to understand how combinations of intraspecific variation in multiple species within an ecosystem impacts its ecology. Using two species that co-occur and demonstrate adaptation to their natal environments, black cottonwood (Populus trichocarpa) and three-spined stickleback (Gasterosteus aculeatus), we investigated the effects of intraspecific phenotypic variation on both top-down and bottom-up forces using a large-scale aquatic mesocosm experiment. Black cottonwood genotypes exhibit genetic variation in their productivity and consequently their leaf litter subsidies to the aquatic system, which mediates the strength of top-down effects from stickleback on prey abundances. Abundances of four common invertebrate prey species and available phosphorous, the most critically limiting nutrient in freshwater systems, are dictated by the interaction between genetic variation in cottonwood productivity and stickleback morphology. These interactive effects fit with ecological theory on the relationship between productivity and top-down control and are comparable in strength to the effects of predator addition. Our results illustrate that intraspecific variation, which can evolve rapidly, is an under-appreciated driver of community structure and ecosystem function, demonstrating that a multi-trophic perspective is essential to understanding the role of evolution in structuring ecological patterns. PMID:26203004

  10. Optical properties of natural dissolved organic matter (DOM) in aquatic ecosystems: Applications in ecosystem studies from headwater streams to the deep ocean. (Invited)

    Science.gov (United States)

    Jaffe, R.

    2010-12-01

    The study of natural dissolved organic material (DOM) contributes to the better understanding of ecosystem function as the carbon flux between environmental compartments represents an important linkage between terrestrial and aquatic ecosystems. Within freshwater and marine ecosystems, DOM typically represents the largest pool of detrital organic carbon and greatly exceeds the organic carbon present in living biomass. Thus, the sources and fate of DOM are important terms in carbon budgets. DOM can also influence ecosystem function by controlling microbial food webs, act as a means of nutrient transport, buffer pH and influence toxicity and bioavailability of pollutants, among others. DOM composition influences its ‘quality’ and thus its photo- and bio-reactivity, both of which exert a strong control of the diagenetic reworking of this carbon pool. However, the molecular composition of DOM is highly complex and diverse, and its characterization is a serious challenge to analytical chemists. In recent years, several novel analytical approaches to the characterization of DOM have evolved, including those that are highly structure specific and others that provide information on broader molecular characteristics. Whilst the former are usually expensive and time consuming, the latter, often based on optical properties measurements, feature high sample throughput at a reduced cost but at the expense of structural specificity. While both approaches are complementary under ideal conditions, the latter are best suited for studies involving large spatial and temporal scales. The analysis of DOM optical properties, in particular excitation emission matrix (EEM) fluorescence combined with parallel factor analysis (PARAFAC), has emerged as a practical tool for the broad characterization of DOM quality. This presentation will provide examples for the application of EEM-PARAFAC in assessing environmental dynamics of DOM on both spatial and temporal scales, and in both

  11. Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    A. P. F. Pires

    Full Text Available Abstract Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems.

  12. Bioindication in natural-like aquatic ecosystems: endocrine disruptors in outdoor microcosms. Status-report

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, K.W.; Severin, G.F.

    2002-07-01

    Over the past few decades scientists have shown that the hormone system of a wide range of organisms can be affected by numerous environmental chemicals. Society strongly demands studies about the fate and effects of such endocrine disruptors on the aquatic environment. It has been scientifically accepted that risk assessment studies done in aquatic microcosms can be used to extrapolate the potential impact of the tested compound on natural ecosystems. Realistic exposure situations were simulated and screening methods as well as analytical methods with high accuracy were applied on water and sediment. For the comprehensive risk assessment as many trophic levels as possible have to be investigated. Changes in the population dynamics and the community structure serve as ecotoxicological endpoints. Modelling the concentrations of the chemicals in the different aquatic compartments complements and confirms the analytical diagnostics. A directed design of the analytical procedures according to amount of sample and limits of determination becomes possible. Bridging acute and chronic time scales in effect diagnostics the 'area under the curve' - approach has been followed in combination with multivariate statistics. Haber's rule have been applied to the results about complex effect- and exposure-conditions. In some cases the interpretation of results becomes more easy and clear by this approach. (orig.)

  13. Direct and indirect effects of temperature on the population dynamics and ecosystem functioning of aquatic microbial ecosystems.

    Science.gov (United States)

    Beveridge, Oliver S; Petchey, Owen L; Humphries, Stuart

    2010-11-01

    1. While much is known about the direct effect that temperature can have on aquatic communities, less is known about its indirect effect via the temperature dependence of viscosity and temperature-dependent trophic interactions. 2. We manipulated the temperature (5-20 °C) and the viscosity (equivalent to 5-20 °C) of water in laboratory-based bacteria-protist communities. Communities contained food chains with one, two or three trophic levels. Responses measured were population dynamics (consumer carrying capacity and growth rate, average species population density, and the coefficient of variation of population density through time) and ecosystem function (decomposition). 3. Temperature, viscosity and food chain length produced significant responses in population dynamics. Temperature-dependent viscosity had a significant effect on the carrying capacity and growth rates of consumers, as well as the average density of the top predator. Overall, indirect effects of temperature via changes in viscosity were subtle in comparison to the indirect effect of temperature via trophic interactions. 4. Our results highlight the importance of direct and indirect effects of temperature, mediated through trophic interactions and physical changes in the environment, both for population dynamics and ecosystem processes. Future mechanistic modelling of effects of environmental change on species will benefit from distinguishing the different mechanisms of the overall effect of temperature.

  14. Diets of aquatic birds reflect changes in the Lake Huron ecosystem

    Science.gov (United States)

    Hebert, Craig E.; Weseloh, D.V. Chip; Idrissi, Abode; Arts, Michael T.; Roseman, Edward F.

    2009-01-01

    Human activities have affected the Lake Huron ecosystem, in part, through alterations in the structure and function of its food webs. Insights into the nature of food web change and its ecological ramifications can be obtained through the monitoring of high trophic level predators such as aquatic birds. Often, food web change involves alterations in the relative abundance of constituent species and/or the introduction of new species (exotic invaders). Diet composition of aquatic birds is influenced, in part, by relative prey availability and therefore is a sensitive measure of food web structure. Using bird diet data to make inferences regarding food web change requires consistent measures of diet composition through time. This can be accomplished by measuring stable chemical and/or biochemical “ecological tracers” in archived avian samples. Such tracers provide insights into pathways of energy and nutrient transfer. In this study, we examine the utility of two groups of naturally-occurring intrinsic tracers (stable isotopes and fatty acids) to provide such information in a predatory seabird, the herring gull (Larus argentatus). Retrospective stable nitrogen and carbon isotope analysis of archived herring gull eggs identified declines in gull trophic position and shifts in food sources in Lake Huron over the last 25 years and changes in gull diet composition were inferred from egg fatty acid patterns. These independent groups of ecological tracers provided corroborating evidence of dietary change in this high trophic level predator. Gull dietary shifts were related to declines in prey fish abundance which suggests large-scale alterations to the Lake Huron ecosystem. Dietary shifts in herring gulls may be contributing to reductions in resources available for egg formation. Further research is required to evaluate how changes in resource availability may affect population sustainability in herring gulls and other waterbird species. Long-term biological monitoring

  15. Cross-ecosystem fluxes: Export of polyunsaturated fatty acids from aquatic to terrestrial ecosystems via emerging insects.

    Science.gov (United States)

    Martin-Creuzburg, Dominik; Kowarik, Carmen; Straile, Dietmar

    2017-01-15

    Cross-ecosystem fluxes can crucially influence the productivity of adjacent habitats. Emerging aquatic insects represent one important pathway through which freshwater-derived organic matter can enter terrestrial food webs. Aquatic insects may be of superior food quality for terrestrial consumers because they contain high concentrations of essential polyunsaturated fatty acids (PUFA). We quantified the export of PUFA via emerging insects from a midsize, mesotrophic lake. Insects were collected using emergence traps installed above different water depths and subjected to fatty acid analyses. Insect emergence from different depth zones and seasonal mean fatty acid concentrations in different insect groups were used to estimate PUFA fluxes. In total, 80.5mg PUFA m(-2)yr(-1) were exported, of which 32.8mgm(-2)yr(-1) were eicosapentaenoic acid (EPA), 7.8mgm(-2)yr(-1) were arachidonic acid (ARA), and 2.6mgm(-2)yr(-1) were docosahexaenoic acid (DHA). While Chironomidae contributed most to insect biomass and total PUFA export, Chaoborus flavicans contributed most to the export of EPA, ARA, and especially DHA. The export of total insect biomass from one square meter declined with depth and the timing at which 50% of total insect biomass emerged was correlated with the water depths over which the traps were installed, suggesting that insect-mediated PUFA fluxes are strongly affected by lake morphometry. Applying a conceptual model developed to assess insect deposition rates on land to our insect-mediated PUFA export data revealed an average total PUFA deposition rate of 150mgm(-2)yr(-1) within 100m inland from the shore. We propose that PUFA export can be reliably estimated using taxon-specific information on emergent insect biomass and seasonal mean body PUFA concentrations of adult insects provided here. Our data indicate that insect-mediated PUFA fluxes from lakes are substantial, implying that freshwater-derived PUFA can crucially influence food web processes in adjacent

  16. Responses of aquatic ecosystems to environmental changes in Finland and China

    Directory of Open Access Journals (Sweden)

    Jan eWeckström

    2015-11-01

    Full Text Available The concern for the state of global freshwater reservoirs has increased due to deterioration of the water quality during the last decades. This has prompted monitoring and restoration efforts such as the European Water Framework Directive and the national-scale 2nd-investigation and monitoring of the water quality, water volume and biota resources in China. The challenge so far has been the determination of the natural state (reference conditions of freshwater ecosystems. We used the sediment archives of five lakes and one brackish water embayment in Finland and China to assess the impact of selected variables of climatology, hydrology, nutrients, and changes in human population on these ecosystems during the last few centuries. The study sites represent catchment areas with varying land use. Despite the long distance between the sites and their different land-use characteristics, the direction and timing of changes during the last few centuries are well comparable between the high latitudes of Finland and the mid-low latitudes of China. This study reinforces the sensitivity of aquatic ecosystems to environmental change and underlines the usefulness of the palaeolimnological approach as a tool for determining reference conditions.

  17. [Aquatic ecosystem modelling approach: temperature and water quality models applied to Oualidia and Nador lagoons].

    Science.gov (United States)

    Idrissi, J Lakhdar; Orbi, A; Hilmi, K; Zidane, F; Moncef, M

    2005-07-01

    The objective of this work is to develop an aquatic ecosystem and apply it on Moroccan lagoon systems. This model will keep us abreast of the yearly development of the main parameters that characterize these ecosystems while integrating all the data that have so far been acquired. Within this framework, a simulation model of the thermal system and a model of the water quality have been elaborated. These models, which have been simulated on the lagoon of Oualidia (North of Morocco) and validated on the lagoon of Nador (North West Mediterranean), permit to foresee the cycles of temperature of the surface and the parameters of the water quality (dissolved oxygen and biomass phytoplankton) by using meteorological information, specific features and in situ measurements in the studied sites. The elaborated model, called Zero-Dimensional, simulates the average conduct of the site during the time of variable states that are representatives of the studied ecosystem. This model will provide answers for the studied phenomena and is a work tool adequate for numerical simplicity.

  18. Sedimentation plan to assess the impact of geothermal activities to the aquatic ecosystem in the Geyers Calistoga KGRA

    Energy Technology Data Exchange (ETDEWEB)

    Ireland, R.R.

    1981-05-19

    The prevention of sedimentation or siltation in aquatic ecosystems is always a key environmental issue in the development and operation of power plant units. This report describes a field program which will assess the amount of sedimentation in the streams and tributaties of the Geysers-Calistoga Known Geothermal Resource Area (KGRA) due to development-related or other site-specific activities. This sediment plan is one part of a four part venture - the others are water quality, benthic invertebrates and fisheries studies - initiated by the California Energy Commission and involving numerous California organizations. Included in this report are the cost breakdowns for each phase, maps and rationale of the sampling sites, the methodology for the laboratory sample processing, and examples of the type of graphic and tabular output expected.

  19. Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

    Science.gov (United States)

    Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Ellis, J.; Woodruff, D.; Quattrochi, D.; Rose, K.; Swann, R.

    2012-12-01

    Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

  20. Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

    Science.gov (United States)

    Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Woodruff, D.; Ellis, J. T.; Quattrochi, D.; Swann, R.

    2012-01-01

    Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

  1. The Life Cycle of Mercury Within the Clear Lake Aquatic Ecosystem: From Ore to Organism

    Science.gov (United States)

    Suchanek, T. H.; Suchanek, T. H.; Nelson, D. C.; Nelson, D. C.; Zierenberg, R. A.; King, P.; King, P.; McElroy, K.; McElroy, K.

    2001-12-01

    Clear Lake (Lake County) is located in the geologically active Clear Lake volcanics mercury (Hg) bearing Franciscan formation within the Coast Range of California, which includes over 300 abandoned Hg mines and prospects. Intermittent mining at the Sulphur Bank Mercury Mine (from 1872-1957), now a USEPA SuperFund site, has resulted in approximately 100 metric tonnes of Hg being deposited into the aquatic ecosystem of Clear Lake, with sediment concentrations of total-Hg as high as 650 mg/kg (parts per million = ppm) near the mine, making Clear Lake one of the most Hg contaminated lakes in the world. As a result, largemouth bass and other top predatory fish species often exceed both the Federal USFDA recommended maximum recommended concentrations of 1.0 ppm and the State of California level of 0.5 ppm. Acid rock drainage leaches Hg and high concentrations of sulfate from the mine site through wasterock and subsurface conduits through subsediment advection and eventually upward diffusion into lake sediments and water. When mineral-laden pH 3 fluids from the mine mix with Clear Lake water (pH 8), an alumino-silicate precipitate (floc) is produced that promotes the localized production of toxic methyl Hg. Floc "hot spots" in sediments near the mine exhibit low pH, high sulfate, anoxia and high organic loading which create conditions that promote Hg methylation by microbial activity, especially in late summer and fall. Wind-driven currents transport methyl-Hg laden floc particles throughout Clear Lake, where they are consumed by plankton and benthic invertebrates and bioaccumulated throughout the food web. While Clear Lake biota have elevated concentrations of methyl-Hg, they are not as elevated as might be expected based on the total Hg loading into the lake. A science-based management approach, utilizing over 10 years of data collected on Hg cycling within the physical and biological compartments of Clear Lake, is necessary to affect a sensible remediation plan.

  2. Microsatellite markers for Nuphar japonica (Nymphaeaceae), an aquatic plant in the agricultural ecosystem of Japan1

    Science.gov (United States)

    Kondo, Toshiaki; Watanabe, Sonoko; Shiga, Takashi; Isagi, Yuji

    2016-01-01

    Premise of the study: Nuphar species (Nymphaeaceae) are representative aquatic plants in irrigation ponds in Japanese agricultural ecosystems. We developed 15 polymorphic microsatellite markers for N. japonica and confirmed their utility for its close relatives N. oguraensis var. akiensis and N. ×saijoensis, which originated from natural hybridization between N. japonica and N. oguraensis. Methods and Results: Genetic variation was characterized in 15 polymorphic loci in three populations of N. japonica. The average number of alleles per locus was 3.47 (range = 2−9; n = 32), and the average expected heterozygosity per locus was 0.84 (range = 0.5–1.0); 11 loci were amplified in N. oguraensis var. akiensis and 15 in N. ×saijoensis. Conclusions: The polymorphic microsatellite markers developed in this study will be useful for investigating the levels of genetic diversity within remnant populations of Nuphar taxa and could provide a valuable tool for conservation genetics of these taxa. PMID:28101435

  3. Mapping critical loads of nitrogen deposition for aquatic ecosystems in the Rocky Mountains, USA

    Science.gov (United States)

    Nanus, Leora; Clow, David W.; Saros, Jasmine E.; Stephens, Verlin C.; Campbell, Donald H.

    2012-01-01

    Spatially explicit estimates of critical loads of nitrogen (N) deposition (CLNdep) for nutrient enrichment in aquatic ecosystems were developed for the Rocky Mountains, USA, using a geostatistical approach. The lowest CLNdep estimates (-1 yr-1) occurred in high-elevation basins with steep slopes, sparse vegetation, and abundance of exposed bedrock and talus. These areas often correspond with areas of high N deposition (>3 kg N ha-1 yr-1), resulting in CLNdep exceedances ≥1.5 ± 1 kg N ha-1 yr-1. CLNdep and CLNdep exceedances exhibit substantial spatial variability related to basin characteristics and are highly sensitive to the NO3- threshold at which ecological effects are thought to occur. Based on an NO3- threshold of 0.5 μmol L-1, N deposition exceeds CLNdep in 21 ± 8% of the study area; thus, broad areas of the Rocky Mountains may be impacted by excess N deposition, with greatest impacts at high elevations.

  4. Introduction to the effects of wildland fire on aquatic ecosystems in the Western USA

    Science.gov (United States)

    Rieman, B.; Gresswell, Robert E.; Young, M.; Luce, C.

    2003-01-01

    The management of wildfire has long been controversial. The role of fire and fire-related management in terrestrial and aquatic ecosystems has become an important focus in recent years, but the general debate is not new. In his recent book, Stephen Pyne (2001)describes the political and scientific debate surrounding the creation of the U.S. Forest Service and the emergence of fire suppression as a central tenet of wildland management. Essentially, views in the first decade of the 20th century focused on fire as good or evil: a tool that might benefit other resources or interests (e.g. Indian burning) and mitigate larger more destructive fires, or a threat to the recruitment and productivity of newly designated forest reserves. The “great fires” in the Western USA in 1910 and the associated loss of human life and property largely forged the public and political will to suppress fire on a massive scale.

  5. Current levels and trends of radioactive contamination of aquatic ecosystem components in the Chernobyl exclusion zone

    Energy Technology Data Exchange (ETDEWEB)

    Gudkov, Dmitri I.; Kaglyan, Alexander Ye.; Ganzha, Kristina D.; Klenus, Vasiliy G. [Institute of Hydrobiology, Geroyev Stalingrada Ave. 12, UA-04210 Kiev (Ukraine); Kireev, Sergey I.; Nazarov, Alexander B. [Chernobyl Specialized Enterprise, Radyanska Str. 70, UA-07270 Chernobyl (Ukraine)

    2014-07-01

    The current radiation level and its composition in aquatic ecosystems within the Chernobyl exclusion zone (ChEZ) are conditioned, above all things, by the amount of radioactive matters released as aerosols on a water surface and adjacent territories during the period of the active phase of the accident from destroyed of the Chernobyl NPP in 1986, and also by intensity and duration of the second processes of radionuclides washout from the catchment areas and hydrodynamic processes of their transport outside of water bodies. During last 10-15 years in the soils of the ChEZ the tendency of increase of yield of the mobile bioavailable forms of radionuclides, which released into hydrological systems with surface and ground waters or localized in the closed water systems, where quickly involving in the biotic cycle is marked. On the example of lakes of the Krasnensky flood plain of the Pripyat River, which is one of the most contaminated by radionuclides territory of the ChEZ, was determined that the basic amount of radionuclides in lake ecosystem is deposited in the bottom sediments: {sup 90}Sr - 89-95%, {sup 137}Cs - 99%, transuranium elements (TUE) {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am - almost 100% of the total radionuclide amount in ecosystem. The increased migration activity of {sup 90}Sr determines its more high quantity in water (4-10%) on comparison with {sup 137}Cs (0.5-0.6%) and TUE (0.03-0.04%) and, opposite, less - in seston (0.15-0.16%) on comparison with {sup 137}Cs (0.25-0.30%). The value of {sup 90}Sr in biotic component amounts 0.25-0.61%, {sup 137}Cs - 0.14-0.47% and TUE - 0.07-0.16% of the total quantity in ecosystem. The gradual decline of radionuclide specific activity is a dominant tendency in the dynamics of {sup 137}Cs and {sup 90}Sr in water and aquatic biota of the majority of reservoirs and water flow in the ChEZ. The exception is water bodies, located on the dammed territories of the Krasnensky flood plain, where at the proceeding

  6. Trophic interactions determine the effects of drought on an aquatic ecosystem.

    Science.gov (United States)

    Amundrud, Sarah L; Srivastava, Diane S

    2016-06-01

    Species interactions can be important mediators of community and ecosystem responses to environmental stressors. However, we still lack a mechanistic understanding of the indirect ecological effects of stress that arise via altered species interactions. To understand how species interactions will be altered by environmental stressors, we need to know if the species that are vulnerable to such stressors also have large impacts on the ecosystem. As predators often exhibit certain traits that are linked to a high vulnerability to stress (e.g., large body size, long generation time), as well as having large effects on communities (e.g., top-down trophic effects), predators may be particularly likely to mediate ecological effects of environmental stress. Other functional groups, like facilitators, are known to have large impacts on communities, but their vulnerability to perturbations remains undocumented. Here, we use aquatic insect communities in bromeliads to examine the indirect effects of an important stressor (drought) on community and ecosystem responses. In a microcosm experiment, we manipulated predatory and facilitative taxa under a range of experimental droughts, and quantified effects on community structure and ecosystem function. Drought, by adversely affecting the top predator, had indirect cascading effects on the entire food web, altering community composition and decomposition. We identified the likely pathway of how drought cascaded through the food web from the top-down as drought -->predator --> shredder --> decomposition. This stress-induced cascade depended on predators exhibiting both a strong vulnerability to drought and large impacts on prey (especially shredders), as well as shredders exhibiting high functional importance as decomposers.

  7. Human impacts, climate change, and aquatic ecosystem response during the past 2000 yr at Lake Wandakara, Uganda

    Science.gov (United States)

    Russell, James M.; McCoy, S. J.; Verschuren, D.; Bessems, I.; Huang, Y.

    2009-11-01

    Analyses of carbon and hydrogen isotope ratios of terrestrial leaf waxes and the carbon and nitrogen abundance, ratio, and isotopic composition of bulk sediments from Lake Wandakara, a crater lake in western Uganda, East Africa, document human and climatic controls on the aquatic system and on the surrounding terrestrial vegetation during the past two millennia. Our data indicate that Wandakara was a relatively stable, productive lake surrounded by C 3 vegetation from AD 70 to 1000. Abrupt changes in the δ 13C of terrestrial leaf waxes indicate a series of abrupt shifts in the relative abundance of C 3 and C 4 vegetation caused by a combination of climate change and human activities around Wandakara beginning at AD 1000. Abrupt shifts in bulk sediment organic geochemistry, particularly C/N ratios and δ 15N, indicate that human activities at this time caused permanent changes in the limnology of Lake Wandakara, including eutrophication. Our results suggest that the biogeochemistry of Lake Wandakara was more sensitive to shifting human impacts than to climate variations during the past millennium, highlighting the importance of understanding the intensity of pre-colonial human impacts on Africa's aquatic ecosystems.

  8. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India

    Energy Technology Data Exchange (ETDEWEB)

    Jha, V.N., E-mail: jhavn1971@gmail.com; Tripathi, R.M., E-mail: tripathirm@yahoo.com; Sethy, N.K., E-mail: sethybarc@rediffmail.com; Sahoo, S.K., E-mail: sksbarc@gmail.com

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r = 0.86, p < 0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r = 0.88, p < 0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p < 0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. - Highlights: • Uranium mill tailings pond. • Jaduguda, India. • Fresh water plants. • Uranium uptake. • Relationship of uranium with stable elements.

  9. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Science.gov (United States)

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, pplants significant correlation was found between uranium concentration in plant and the substrate (r=0.88, pplants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p<0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent.

  10. IPH-TRIM3D-PCLake: A three-dimensional complex dynamic model for subtropical aquatic ecosystems

    NARCIS (Netherlands)

    Fragoso, C.R.; Nes, van E.H.; Janse, J.H.; Motta Marques, da D.

    2009-01-01

    This paper presents IPH-TRIM3D-PCLake, a three-dimensional complex dynamic model for subtropical aquatic ecosystems. It combines a spatially explicit hydrodynamic model with a water-quality and biotic model of ecological interactions. The software, which is freely available for research purposes, ha

  11. Novel use of cavity ring-down spectroscopy to investigate aquatic carbon cycling from microbial to ecosystem scales

    NARCIS (Netherlands)

    Maher, D.T.; Santos, I.S.; Leuven, J.R.F.W.; Oakes, J.M.; Erler, D.V.; Carvalho, M.C.; Eyre, B.D.

    2013-01-01

    Development of cavity ring-down spectroscopy (CRDS) has enabled real-time monitoring of carbon stable isotope ratios of carbon dioxide and methane in air. Here we demonstrate that CRDS can be adapted to assess aquatic carbon cycling processes from microbial to ecosystem scales. We first measured in

  12. Integration of aquatic fate and ecological responses to linear alkyl benzene sulfonate (LAS) in model stream ecosystems.

    Science.gov (United States)

    Belanger, S E; Bowling, J W; Lee, D M; LeBlanc, E M; Kerr, K M; McAvoy, D C; Christman, S C; Davidson, D H

    2002-06-01

    An integrated model stream ecosystem fate and effect study of dodecyl linear alkylbenzene sulfonate (C(12)LAS) was performed in the summer and fall of 1996. The study addressed responses of periphytic microbes, immature benthic fauna including abundance, drift, and emergence of adult insects in a 56-day exposure. Exposures ranged from 126 to 2978 microg/L and were continuously presented in a single-pass, flow-through test system. Microbial heterotrophs acclimated to C(12)LAS exposure quickly (14 days) and biodegraded C(12)LAS at all concentrations. Blue-green algae responded by increasing in abundance with increasing C(12)LAS concentration. Invertebrates responded by increased drift and reduced benthic abundances at concentrations exceeding 293 microg/L. Emergence at 927 microg/L also declined relative to the control. Adverse responses for mayflies and chironomids were indicated using univariate statistical techniques. Multivariate techniques indicated these taxa plus mollusks, aquatic worms, caddisflies, and stoneflies were impaired at some concentrations. Bioavailability of C(12)LAS was investigated in streams as a function of the total suspended solid load in the water column driven by local weather and watershed patterns. A continuous bioavailability model indicated exposure was reduced by an average of 8.5+/-8.9%. A model ecosystem no-observed-effect concentration (NOEC) was concluded to be 293 microg/L based on measured water column exposure and adjusted to 268 microg/L by the bioavailability model. A literature review of 13 available model ecosystem studies was conducted and NOEC conclusions were adjusted by a structure-activity relationship to a dodecyl chain length (sulfophenyl position and distribution being ignored due to lack of information in the reviewed studies). Lentic studies (n=7) were found to have higher NOECs than lotic studies (n=6) and were more variable. Mean NOECs+/-SD for all studies, lentic studies only, and lotic studies only were 3320

  13. Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia

    Science.gov (United States)

    Mackay, Anson W.; Bezrukova, Elena V.; Leng, Melanie J.; Meaney, Miriam; Nunes, Ana; Piotrowska, Natalia; Self, Angela; Shchetnikov, Alexander; Shilland, Ewan; Tarasov, Pavel; Wang, Luo; White, Dustin

    2012-05-01

    Boreal ecosystems are highly vulnerable to climate change, and severe ecological impacts in the near future are virtually certain to occur. We undertook a multiproxy study on an alpine lake (ESM-1) at the modern tree-line in boreal, southern Siberia. Steppe and tundra biomes were extensive in eastern Sayan landscapes during the early Holocene. Boreal forest quickly expanded by 9.1 ka BP, and dominated the landscape until c 0.7 ka BP, when the greatest period of compositional turnover occurred. At this time, alpine meadow landscape expanded and Picea obovata colonised new habitats along river valleys and lake shorelines, because of prevailing cool, moist conditions. During the early Holocene, chironomid assemblages were dominated by cold stenotherms. Diatoms for much of the Holocene were dominated by alkaliphilous, fragilarioid taxa, up until 0.2 ka BP, when epiphytic species expanded, indicative of increased habitat availability. C/N mass ratios ranged between 9.5 and 13.5 (11.1-15.8 C/N atomic ratios), indicative of algal communities dominating organic matter contributions to bottom sediments with small, persistent contributions from vascular plants. However, δ13C values increased steadily from -34.9‰ during the early Holocene (9.3 ka BP) to -24.8‰ by 0.6 ka BP. This large shift in magnitude may be due to a number of factors, including increasing within-lake productivity, increasing disequilibrium between the isotopic balance of the lake with the atmosphere as the lake became isotopically ‘mature’, and declining soil respiration linked to small, but distinct retreat in forest biomes. The influence of climatic variables on landscape vegetation was assessed using redundancy analysis (RDA), a linear, direct ordination technique. Changes in July insolation at 60 °N significantly explained over one-fifth of the variation in species composition, while changes in estimates of northern hemisphere temperature and ice-rafted debris events in the North Atlantic

  14. Climate regulates alpine lake ice cover phenology and aquatic ecosystem structure

    Science.gov (United States)

    Preston, Daniel L.; Caine, Nel; McKnight, Diane M.; Williams, Mark W.; Hell, Katherina; Miller, Matthew P.; Hart, Sarah J.; Johnson, Pieter T. J.

    2016-05-01

    High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term data set on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted 7 days earlier over the past 33 years and that spring weather conditions—especially snowfall—drive yearly variation in ice-off timing. In the most well studied lake, earlier ice-off associated with increases in water residence times, thermal stratification, ion concentrations, dissolved nitrogen, pH, and chlorophyll a. Mechanistically, low spring snowfall and warm temperatures reduce summer stream flow (increasing lake residence times) but enhance melting of glacial and permafrost ice (increasing lake solute inputs). The observed links among hydrological, chemical, and biological responses to climate factors highlight the potential for major shifts in the functioning of alpine lakes due to forecasted climate change.

  15. Climate regulates alpine lake ice cover phenology and aquatic ecosystem structure

    Science.gov (United States)

    Preston, Daniel L.; Caine, Nel; McKnight, Diane M.; Williams, Mark W.; Hell, Katherina; Miller, Matthew P.; Hart, Sarah J.; Johnson, Pieter T.J.

    2016-01-01

    High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term dataset on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted seven days earlier over the past 33 years and that spring weather conditions – especially snowfall – drive yearly variation in ice-off timing. In the most well-studied lake, earlier ice-off associated with increases in water residence times, thermal stratification, ion concentrations, dissolved nitrogen, pH, and chlorophyll-a. Mechanistically, low spring snowfall and warm temperatures reduce summer stream flow (increasing lake residence times) but enhance melting of glacial and permafrost ice (increasing lake solute inputs). The observed links among hydrological, chemical, and biological responses to climate factors highlight the potential for major shifts in the functioning of alpine lakes due to forecasted climate change.

  16. A study of 110mAg in aquatic and terrestrial ecosystems.

    Science.gov (United States)

    Shang, Zhaorong; Leung, John K C

    2003-04-01

    Experiments on a simulated terrestrial agricultural ecosystem were carried out using the pot culture approach. The most representative plants in local vegetable gardens were selected to investigate the root uptake of (110m)Ag. The results show that carrot, kale and flowering cabbage have the largest transfer factor values among the vegetables. Flowering cabbage, as the most popular leafy vegetable in Hong Kong and the South China area, can be used as a biomonitor for radioisotope contamination in vegetables. Soil column and adsorption tests were also carried out to study the leaching ability of the silver isotope in soil and (110m)Ag was mainly adsorbed in the top 1 cm of soil regardless of the pH value. Experiments on a simulated aquatic ecosystem for freshwater fish and marine organisms were carried out in glass aquaria. The freshwater fish Cyprinus carpio, the marine fish Cuvier and some local abundant seashore molluscs were selected to investigate the kinetic metabolism of (110m)Ag in the compartmental system. The results show that molluscs absorb (110m)Ag much more than fish. Clibanarius infraspinatus has the largest concentration factor among the marine organisms selected. Fish liver, although representing a minor portion of the total body mass, shows the highest (110m)Ag concentration factor, whereas muscle, although representing a major portion of the total body mass, is characterized by an absence of (110m)Ag.

  17. An assessment of aquatic ecosystem health in a temperate watershed using the index of biological integrity.

    Science.gov (United States)

    An, Kwang-Guk; Choi, Shin-Sok

    2003-06-01

    The health effect of an aquatic ecosystem on habitat modifications were evaluated in the Keum river watershed, Korea during 1977-1996 using the Index of Biological Integrity (IBI) based on fish assemblages. Values of IBI, based on overall sites, averaged 35 (range: 26-45, n = 38) before dam construction, indicating a "fair health condition" based on the modified criteria of Karr and Chu (Karr, J.R.; Chu, E.W. Restoring Life in Running Waters: Better Biological Monitoring; Inland Press: Washington, DC, 1999; 206 pp.), while the values averaged 33 (range: 18-48, n = 15) after dam construction, indicating a similar ecosystem health condition in the IBI between the two periods. Marked modifications in the IBI, however, were partially observed along the longitudinal gradients from the headwaters to downstream along with variations of trophic compositions and habitat guilds. Annual mean of IBI showed significant decreases (p 20% decreases of insectivores and >25% increases of omnivores. Comparisons of habitat guilds indicated that the proportion of riffle benthic species declined linearly from 1977 to 1996 and had inverse relations (r = -0.78, p health was mainly affected by the habitat modifications.

  18. Bioassessment of contaminant transport and distribution in aquatic ecosystems by chemical analysis of burrowing mayflies (Hexagenia)

    Science.gov (United States)

    Steingraeber, M.T.; Wiener, J.G.

    1995-01-01

    Burrowing mayfly nymphs (Ephemeroptera) inhabit and ingest fine-grained sediments and detritus that may be enriched with metals and persistent organic compounds. The burrowing nymphs can externally adsorb and internally assimilate these contaminants, providing a link for the food chain transfer of potentially toxic substances from sediments to organisms in higher trophic levels. The emergent adults are short-lived and do not feed, thus their gut contents do not contribute greatly to their total contaminant burden. These characteristics make Hexagenia spp. And certain other burrowing mayflies useful for assessing ecosystem contamination. General protocols are presented for the collection, processing and analysis of emergent mayflies to assess the spatial distribution and bioaccumulation of sediment-associated contaminants in aquatic ecosystems. Two essential components of this bioassessment approach are a network of on-site volunteers with the materials and instructions needed to correctly collect and store samples and quality assurance procedures to estimate the accuracy of chemical analyses. The utility of this approach is demonstrated with an example of its application to the Upper Mississippi River (USA). Determination of cadmium, mercury and polychlorinated biphenyl congeners in emergent Hexagenia bilineata from a 1250 km reach of this river revealed (1) several source areas of contaminants and (2) distinct patterns in the bioaccumulation (and apparent sediment-associated transport) of each residue on both small and large spatial scales.

  19. Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems

    Science.gov (United States)

    Vonk, J.E.; Tank, S.E.; Bowden, W.B.; Laurion, I.; Vincent, W.F.; Alekseychik, P.; Amyot, Y.; Billet, M.F.; Canario, J.; Cory, R.M.; Deshpande, B.N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; MacMillan, G.; Rautio, M.; Walter Anthony, K.M.; Wickland, Kimberly P.

    2015-01-01

    of dissolved vs. particulate organic matter, coupled with the composition of that organic matter and the morphology and stratification characteristics of recipient systems will play an important role in determining the balance between the release of organic matter as greenhouse gases (CO2 and CH4), its burial in sediments, and its loss downstream. The magnitude of thaw impacts on northern aquatic ecosystems is increasing, as is the prevalence of thaw-impacted lakes and streams. There is therefore an urgent need to quantify how permafrost thaw is affecting aquatic ecosystems across diverse Arctic landscapes, and the implications of this change for further climate warming.

  20. Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems

    Science.gov (United States)

    Vonk, J. E.; Tank, S. E.; Bowden, W. B.; Laurion, I.; Vincent, W. F.; Alekseychik, P.; Amyot, M.; Billet, M. F.; Canário, J.; Cory, R. M.; Deshpande, B. N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; MacMillan, G.; Rautio, M.; Anthony, K. M. Walter; Wickland, K. P.

    2015-12-01

    of dissolved vs. particulate organic matter, coupled with the composition of that organic matter and the morphology and stratification characteristics of recipient systems will play an important role in determining the balance between the release of organic matter as greenhouse gases (CO2 and CH4), its burial in sediments, and its loss downstream. The magnitude of thaw impacts on northern aquatic ecosystems is increasing, as is the prevalence of thaw-impacted lakes and streams. There is therefore an urgent need to quantify how permafrost thaw is affecting aquatic ecosystems across diverse Arctic landscapes, and the implications of this change for further climate warming.

  1. Reviews and Syntheses: Effects of permafrost thaw on arctic aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    J. E. Vonk

    2015-07-01

    enables the delivery of dissolved vs. particulate organic matter, coupled with the composition of that organic matter and the morphology and stratification characteristics of recipient systems will play an important role in determining the balance between the release of organic matter as greenhouse gases (CO2 and CH4, its burial in sediments, and its loss downstream. The magnitude of thaw impacts on northern aquatic ecosystems is increasing, as is the prevalence of thaw-impacted lakes and streams. There is therefore an urgent need to address the key gaps in understanding in order to predict the full effects of permafrost thaw on aquatic ecosystems throughout the Arctic, and their consequential feedbacks to climate.

  2. Sediment composition mediates the invasibility of aquatic ecosystems by a non-native Poaceae species

    Directory of Open Access Journals (Sweden)

    José Vitor Botter Fasoli

    2015-06-01

    Full Text Available Aim: To test the invasibility of aquatic ecosystems by an exotic species, we used the invasive macrophyte Urochloa arrecta, which has invaded many Neotropical waterbodies and has reduced biodiversity in these habitats. The extensive growth of this macrophyte can be related to its affinity for mud-rich sediments, which occur primarily in secondary river channels and lentic habitats.MethodsTo test this hypothesis, we cultivated U. arrecta in trays with different percentages of mud and we measured the sprout length and biomass of the plants after 75 days.ResultsOur results showed a positive and significant relationship between sediment mud percentage and nitrogen, phosphorus and organic matter. Both plant length and biomass increased significantly and continuously with increasing mud content, indicating that the growth of this species is not limited even at the highest levels of mud, which is shown to be toxic for other species of macrophytes. Thus, it is probable that sand-rich sites, such as river shores, are less vulnerable to invasion by this species than relatively mud-rich sites, such as lakes.ConclusionsThis finding indicates that relatively mud-rich ecosystems should be prioritised in monitoring programs to prevent invasion by this species. In addition, the slow development of this species in sandy sediments opens a potential window for its management, at least on small spatial scales. However, despite the reduced growth of U. arrecta in sand-rich sediments, this grass is able to grow in several types of sediments, which explains its spread in a variety of habitats in Neotropical freshwater ecosystems.

  3. Balanced nitrogen economy as a flexible strategy on yield stabilizing and quality of aquatic food crops in wetland ecosystem

    Institute of Scientific and Technical Information of China (English)

    A.; M.; Puste; P.; K.; Sarkar; D.; K.; Das

    2005-01-01

    In wetland ecosystem, nitrogen along with other elements and its management is most imperative for the production of so many aquatic food, non-food and beneficial medicinal plants and for the improvement of soil and water characteristics. With great significant importance of INM (integrated nutrient management) as sources, emphasizing on management on nitrogen as a key element and its divergence, a case study was undertaken on such aquatic food crops (starch and protein-rich, most popular and remunerative) in the farmers' field of low-lying randomized block design, where, three important aquatic food crops (water chestnut (Trapa bispinosa Roxb.), makhana (Eurya/e ferox Salisb.) and water lily (Nymphaea spp.) as major factor and eleven combinations of organic and inorganic sources of nutrients as sub-factor was considered in the experiment. It revealed from the results that the production of fresh kernels or nuts of water chestnut (8.57 t ha-1), matured nut yield of makhana (3.06 t ha-1) and flower stalks of water-lily as vegetables (6.38 t ha-1) including its nutritional quality (starch, protein, sugar and minerals) was remarkably influenced with the application of both organic (neem oilcake @ 0.2 t ha-1) and inorganic sources (NPK @ 30:20:20 kg ha-1 along with spraying of NPK @ 0.5% each over crop canopy at 20 days interval after transplanting) than the other INM combinations applied to the crops. Among the crops, highest WCYE (water chestnut yield equivalence) exhibited in makhana due to its high price of popped-form in the country, which is being exported to other countries at now. Sole application of both (organic and inorganic sources) with lower range did not produce any significant outcome from the study and exhibited lower value for all the crops.Besides production of food crops, INM also greatly influenced the soil and water characterization and it was favourably reflected in this study. The physico-chemical characteristics of soil (textural class, p

  4. Marcellus and mercury: Assessing potential impacts of unconventional natural gas extraction on aquatic ecosystems in northwestern Pennsylvania.

    Science.gov (United States)

    Grant, Christopher J; Weimer, Alexander B; Marks, Nicole K; Perow, Elliott S; Oster, Jacob M; Brubaker, Kristen M; Trexler, Ryan V; Solomon, Caroline M; Lamendella, Regina

    2015-01-01

    Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P shale natural gas exploration is having an effect on aquatic ecosystems.

  5. Transgenic Bacillus thuringiensis (Bt) rice is safer to aquatic ecosystems than its non-transgenic counterpart.

    Science.gov (United States)

    Li, Guangsheng; Wang, Yongmo; Liu, Biao; Zhang, Guoan

    2014-01-01

    Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt) have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt) significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems.

  6. Transgenic Bacillus thuringiensis (Bt rice is safer to aquatic ecosystems than its non-transgenic counterpart.

    Directory of Open Access Journals (Sweden)

    Guangsheng Li

    Full Text Available Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems.

  7. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    quasi-stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K{sub d}, distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the

  8. Impact of external forces on cyanophage-host interactions in aquatic ecosystems.

    Science.gov (United States)

    Jassim, Sabah A A; Limoges, Richard G

    2013-10-01

    Cyanobacterial (algal) blooms have by convention been attributed to the excessive level of nutrients from pollution and runoff, which promotes the rapid growth and multiplication of cyanobacteria or algae. The cyanophage (virus) is the natural predator of cyanobacteria (the host). The aim of this review is to unveil certain pressures that disrupt cyanophage-host interactions and the formation of cyanobacterial blooms. This review focuses principally on the impact of greenhouse gases, ozone depletion, solar ultraviolet radiation (SUR) and the role of recently discovered virophages, which coexist with and in turn are the natural predator of phages. The key findings are that the increase in SUR, the mutation of cyanophages and cyanobacteria, along with changing nutrient levels, have combined with virophages to impede cyanophage-host interactions and the resultant viral infection and killing of the cyanobacterial cell, which is a necessary step in controlling cyanobacterial blooms. Consider this a 'call to action' for researchers interested in corrective action aimed at evolving aquatic ecosystems.

  9. Ecological risk assessment of zinc from stormwater runoff to an aquatic ecosystem.

    Science.gov (United States)

    Brix, Kevin V; Keithly, James; Santore, Robert C; DeForest, David K; Tobiason, Scott

    2010-03-15

    Zinc (Zn) risks from stormwater runoff to an aquatic ecosystem were studied. Monitoring data on waterborne, porewater, and sediment Zn concentrations collected at 20 stations throughout a stormwater collection/detention facility consisting of forested wetlands, a retention pond and first order stream were used to conduct the assessment. Bioavailability in the water column was estimated using biotic ligand models for invertebrates and fish while bioavailability in the sediment was assessed using acid volatile sulfide-simultaneously extracted metal (AVS-SEM). The screening level assessment indicated no significant risks were posed to benthic organisms from Zn concentrations in sediments and pore water. As would be expected for stormwater, Zn concentrations were temporally quite variable within a storm event, varying by factors of 2 to 4. Overall, probabilistic assessment indicated low (5-10% of species affected) to negligible risks in the system, especially at the discharge to the first order stream. Moderate to high risks (10-50% of species affected) were identified at sampling locations most upgradient in the collection system. The largest uncertainty with the assessment is associated with how best to estimate chronic exposure/risks from time-varying exposure concentrations. Further research on pulse exposure metal toxicity is clearly needed to assess stormwater impacts on the environment.

  10. A methodological approach to characterize the resilience of aquatic ecosystems with application to Lake Annecy, France

    Science.gov (United States)

    Pinault, J.-L.; Berthier, F.

    2007-01-01

    We propose a methodological approach to characterize the resilience of aquatic ecosystems with respect to the evolution of environmental parameters as well as their aptitude to adapt to forcings. This method that is applied to Lake Annecy, France, proceeds in three stages. First, according to the depth, variations of physicochemical parameters versus time are separated into three components related to (1) energy transfer through the surface of the lake, (2) the flow of rivers and springs that feed the lake, and (3) long-term evolution of the benthic zone as a consequence of mineral and organic matter loads. Second, dynamics of the lake are deduced by analyzing the physicochemical parameter components related to the three boundary conditions. Third, a stochastic process associated with the transfer models aims to characterize the resilience of the lakes according to forcings. For Lake Annecy, whose dynamics are representative of oligotrophic stratified lakes controlled by decarbonation processes where turnover and mixing occurring once a year in winter, the major consequence is the impoverishment of dissolved oxygen in deep water in autumn due to a temperature increase of the surface water in summer. The simulation raises relevant questions about whether a connection exists between physicochemical parameters and global warming, which should not induce harmful consequences on water quality and biodiversity in deep water. This methodological approach is general since it does not use any physical conceptual model to predict the hydrosystem behavior but uses directly observed data.

  11. Scaling relationships among drivers of aquatic respiration from the smallest to the largest freshwater ecosystems

    Science.gov (United States)

    Hall, Ed K; Schoolmaster, Donald; Amado, A.M; Stets, Edward G.; Lennon, J.T.; Domaine, L.; Cotner, J.B.

    2016-01-01

    To address how various environmental parameters control or constrain planktonic respiration (PR), we used geometric scaling relationships and established biological scaling laws to derive quantitative predictions for the relationships among key drivers of PR. We then used empirical measurements of PR and environmental (soluble reactive phosphate [SRP], carbon [DOC], chlorophyll a [Chl-a)], and temperature) and landscape parameters (lake area [LA] and watershed area [WA]) from a set of 44 lakes that varied in size and trophic status to test our hypotheses. We found that landscape-level processes affected PR through direct effects on DOC and temperature and indirectly via SRP. In accordance with predictions made from known relationships and scaling laws, scale coefficients (the parameter that describes the shape of a relationship between 2 variables) were found to be negative and have an absolute value 1, others small pond catchments to the largest body of freshwater on the planet, Lake Superior, these findings should be applicable to controls of PR for the great majority of temperate aquatic ecosystems.

  12. Extraordinary stability of copper(I)-tetrathiomolybdate complexes: possible implications for aquatic ecosystems.

    Science.gov (United States)

    Helz, George R; Erickson, Britt E

    2011-01-01

    An extraordinary affinity of MoS₄²⁻ for Cu accounts for Mo-induced Cu deficiency in ruminants (molybdenosis) and offers an approach to treating Wilson's disease in humans. Evidence of thiomolybdates in sulfidic natural waters, and possibly even as metastable traces in oxic natural waters, raises the question of how Cu-Mo affinity might affect Cu availability or toxicity in aquatic ecosystems. Stabilities of inorganic Cu-MoS₄²⁻ complexes are characterized and quantified here for the first time. Two remarkably stable Cu(I) dissolved complexes are identified (T = 23°C ± 2°C): Cu₂(HS)₂MoS₄²⁻ and Cu₂S₂MoS₄⁴⁻. In addition, the solubility constant for a precipitate (NH₄CuMoS₄) was measured. Under the extremely reducing conditions in rumen fluids, these complexes will greatly suppress Cu(+) activity, supporting prior conclusions about the mechanism of molybdenosis. In sulfidic natural waters, they help to prevent complete Cu impoverishment, as might otherwise occur by sulfide mineral precipitation. On the other hand, the complexes discovered here are HS⁻-dependent and could not be important in oxic natural waters (with HS⁻ concentrations < 10⁻⁹ M) even if metastable, biogenic MoS₄²⁻ indeed were present as previously conjectured.

  13. Mercury cycling in aquatic ecosystems and trophic state-related variables--implications from structural equation modeling.

    Science.gov (United States)

    Pollman, Curtis D

    2014-11-15

    Structural equation modeling (SEM) provides a framework that can more properly handle complex variable interactions inherent in mercury cycling and its bioaccumulation compared to more traditional regression-based methods. SEM was applied to regional data sets for three different types of aquatic ecosystems within Florida, USA--lakes, streams, and the Everglades--to evaluate the underlying nature (i.e., indirect and direct) of the relationships between fish mercury concentrations and trophic state related variables such as nutrients, dissolved organic carbon (DOC), sulfate, and alkalinity. The modeling results indicated some differences in key variable relationships--for example, the effect of nutrients on fish mercury in lakes and streams was uniformly negative through direct and indirect pathways consistent with biodilution or eutrophication-associated effects on food web structure. Somewhat surprisingly, however, was that total phosphorus did not serve as a meaningful variable in the Everglades model, apparently because its effects were masked or secondary to the effects of DOC. What is perhaps a more important result were two key similarities across the three systems. First, the modeling clearly indicates that the dominant influence on fish tissue mercury concentrations in all three systems is related to variations in the methylmercury signal. Second, the modeling demonstrated that the effect of DOC on fish mercury concentrations was exerted through multiple and antagonistic pathways, including facilitated transport of total mercury and methylmercury, enhanced rates of methylation, and limitations imposed on bioavailability. Indeed, while the individual DOC pathways in the models were all highly significant (generally pmodel was greatly reduced or insignificant. These results can help explain contradictory results obtained previously by other researchers in other systems, and illustrate the importance of SEM as a modeling tool when studying systems with complex

  14. Old river beds under urbanization pressure. Can we protect valuable aquatic ecosystems within the cities?

    Science.gov (United States)

    Sikorska, Daria; Sikorski, Piotr

    2016-04-01

    Old river channels are valuable ecosystems in the scale of whole Europe. Protected as Natura 2000 habitats they are characterized by high biodiversity and provide various ecosystem services. River regulation, eutrophication or lack of annual flooding result in an impoverishment and disappearance of these habitats. Moreover they are subjected to severe pressure from uncontrolled expansion of the cities. The aim of this study was to determine factors associated with urbanization mostly contributing to impoverishment of the vegetation associated with the old channels and to identify landscape characteristics favouring high diversity and naturalness. We were seeking for indices that could be implemented in spatial management for preservation of these ecosystems. Vegetation inventory of 28 lakes, being former river Vistula beds near Warsaw was held. The lakes were located in an urban-rural gradient from the city centre, suburban zone to rural areas. Mapping of vegetation was performed for aquatic vegetation, rushes and vegetation of the shores (321 relevés). Human pressure was assessed on the basis of landscape composition of the lakes neighbourhood, characteristic features of the reservoir and water physio-chemical properties. High diversity and naturalness of the vegetation associated with former Vistula River beds was proved. Effects of the human pressure in the vegetation composition were recognized in high share of alien species and impoverishment of native plants. Composition was dependant on the intensity of human pressure in the neighbourhood and was mostly related to percentage of built-up areas and road density. Selected measures allowed to explain not more than 30% of plants composition variation which implies strong effect of local factors. Vegetation composition of former river beds changed significantly along urban-rural gradient, though the trend could be noted only to the city border. Several protection activities were proposed favouring high

  15. The influence of ecological processes on the accumulation of persistent organochlorines in aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Olof

    1999-09-01

    Several ecological problems influences the fate, transport, and accumulation of persistent organochlorines (OCs) in aquatic ecosystems. In this thesis, I have focused on two processes, namely (i) the food chain bioaccumulation of OCs, and (ii) the trophic status of the aquatic system. To test the biomagnification theory, I investigated PCB concentrations in planktonic food chains in lakes. The concentrations of PCB on a lipid basis did not increase with increasing trophic level. Hence, I could give no support to the theory of biomagnification. Instead, lipid content explained most of the variation in PCB accumulation in these food chains. PCBs were differentially fractionated in the food chains, the relative amount of high molecular weight PCBs increased with increasing trophic level, indicating congener specific differences in either the accumulation or the elimination of PCBs at the different trophic levels. In another study, I investigated the relationship between OC concentrations and trophic level, measured as {delta}{sup 15}N, in a specific predatory fish population. The dry weight OC concentrations and {delta}{sup 15}N were related, indicating effects of prey choice on the OC accumulation. However, here also, lipid content explained the major part of the variation in OC concentrations, independent of trophic level (e. g. {delta}{sup 15}N). I investigated the effects of trophic status, measured as Tot-P concentration in water, on the concentrations of OCs in water, planktonic food chains and sediment in lakes. The dry weight concentrations of PCBs in phytoplankton were negatively related to the trophic status of the lakes. However, this relationship was explained by the decreasing lipid content of phytoplankton with lake trophic status. The phytoplankton in eutrophic lakes had lower lipid content than phytoplankton in oligotrophic lakes, possibly due to inter- and intraspecific differences in lipid content due to nutrient stress. The sediment accumulation and

  16. Ecotoxicological monitoring for the evaluation of environmental recovery of aquatic ecosystems using Poecilia reticulata

    Energy Technology Data Exchange (ETDEWEB)

    DaSilva, E.M.; Navarro, M.F.T.; Mota, M.F.; Chastinet, C.B.A.

    1995-12-31

    Groundwater contamination has led to a considerable environmental impact on the humic acid-rich lake systems of Jaua and Interiagos (Camagari-BA). This was caused by the seepage of rainwater through a dune, which was used for some time as a dumping ground of a titanium dioxide plant. The pH fall in the water has conducted to a precipitation of the humic acids and the disappearance of the local fish fauna. The plant (TIBRAS S/A) initiated a recovery program in 1992 to seal up the contaminated dune, thus avoiding further contamination of the groundwater. During the last two years, ecotoxicity tests have been carried out with lake water, employing young individual of the guppy (Poecilia reticulate), an endemic species, as a test organism. Results for 1993 indicated and confined the contamination of five water stations from a total of eight sampled nearby. The LT{sub 50} were in some cases lower than 60 min. In the end of 1993, a severe drought caused the total disappearance of the surface water in the whole aquatic ecosystem. In May 1994, the testing series restarted and some considerable changes have been detected: the return of the water color for the whole system, an increase in pH and a considerable decrease of toxicity in two other stations. LT{sub 50} values for five stations were above 96 hours. These results are not yet an indicative that the dune sealing has been carried out properly, but are able to show and follow improvements in the biological quality of water bodies.

  17. Effect of pesticides used in banana and pineapple plantations on aquatic ecosystems in Costa Rica.

    Science.gov (United States)

    Diepens, Noël J; Pfennig, Sascha; Van den Brink, Paul J; Gunnarsson, Jonas S; Ruepert, Clemens; Castillo, Luisa E

    2014-01-01

    Current knowledge on fate and effect of agricultural pesticides comes is mainly from temperate ecosystems. More studies are needed in tropical systems in order to assess contamination risks to nontarget endemic tropical species from the extensive use of pesticides e.g. in banana and pineapple plantations. In this study, acute laboratory toxicity tests with organophosphate pesticides ethoprophos and chlorpyrifos were conducted on two Costa Rican species, cladoceran Daphnia ambigua and fish Parachromis dovii. Tests showed that chlorpyrifos was more toxic than ethoprophos to D. ambigua and P. dovii and that D. ambigua was also more sensitive than P. dovii to both pesticides. Additionally, bioassays were performed by exposing D. magna and P. dovii to contaminated water collected from the field. Chemical analyses of field water revealed that fungicides were generally the most frequent pesticide group found, followed by insecticides/nematicides and herbicides. The bioassays and values obtained from the literature confirmed that D. magna was more sensitive to pesticide contamination than P. dovii and that D. ambigua was more sensitive than D. magna, suggesting that the native cladoceran is a more suitable test species than its temperate counterpart. Species sensitivity distributions showed no significant difference in sensitivity between tropical and temperate fish and the arthropod species exposed to chlorpyrifos in this study. Choline esterase activity (ChE) was measured in P. dovii in laboratory tests in order to assess the applicability of this biomarker. ChE inhibition in P. dovii was observed in the laboratory at levels below the LC10 of both ethoprophos and chlorpyrifos, confirming that ChE is an efficient biomarker of exposure. Both indigenous Costa Rican species used in this study were found to be suitable standard tropical test species. Further studies are needed to investigate how protective the safe environmental concentrations, derived from LC50 of native

  18. Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

    Science.gov (United States)

    Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.; Judd, Chaeli; Thom, Ron; Woodruff, Dana; Ellis, Jean T.; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

    2012-01-01

    Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

  19. Models for transport and fate of carbon, nutrients and radionuclides in the aquatic ecosystem at Oeregrundsgrepen

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe; Sandberg, Johannes (DHI, Hoersholm (Denmark))

    2010-06-15

    quasi-stationary equilibrium within the model area. The coupled ecosystem and radionuclide models were used to simulate present conditions, i.e. 2020 AD. Six radionuclides were modelled explicitly in addition to C-14. They represent a wide range of accumulation potentials and partition coefficients (K{sub d}, distribution of radionuclides between water, sediment and biota). The ecosystem and associated radionuclide model include a detailed sediment module where radionuclides can be bound by adsorption to the organic and inorganic fractions, be precipitated, be transported by resuspension and later deposited at larger depths. With the exception of radionuclides with very low particle affinity, such as Cl-35, the majority of radionuclides released in basins where they were introduced via groundwater flow remained in the sediments even after a simulation period of eight years. The spread of radionuclides with high partition coefficients for sediments from areas with groundwater flow takes place by sediment resuspension and subsequent transport and sedimentation. In the case of radionuclides with lower partition coefficients, release from the sediments to the water column followed by transport of dissolved radionuclides by currents plays a larger role. A significant result of the modelling was the quantification of the seasonal and spatial variation in radionuclide accumulation and in bioconcentration factors (BCFs) with spatial variation of BCFs often ranging 2 to 3 orders of magnitude. This variation was dominated by spatial differences in concentrations of radionuclides in water. In basins where radionuclides were introduced by groundwater flow, BCFs were typically 2-3 orders of magnitude lower than in deep basins without radionuclide release in the groundwater. In phytoplankton and grazers, bioconcentration factors (BCFs) scaled linearly to partition coefficients (Kd), underlining the fact that adsorption is an important process for radionuclide accumulation in the

  20. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project

    Science.gov (United States)

    Navarro-Ortega, Alícia; Acuña, Vicenç; Bellin, Alberto; Burek, Peter; Cassiani, Giorgio; Choukr-Allah, Redouane; Dolédec, Sylvain; Elosegi, Arturo; Ferrari, Federico; Ginebreda, Antoni; Grathwohl, Peter; Jones, Colin; Rault, Philippe Ker; Kok, Kasper; Koundouri, Phoebe; Ludwig, Ralf Peter; Merz, Ralf; Milacic, Radmila; Muñoz, Isabel; Nikulin, Grigory; Paniconi, Claudio; Paunović, Momir; Petrovic, Mira; Sabater, Laia; Sabaterb, Sergi; Skoulikidis, Nikolaos Th.; Slob, Adriaan; Teutsch, Georg; Voulvoulis, Nikolaos; Barceló, Damià

    2015-01-01

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA. PMID:25005236

  1. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity. The GLOBAQUA project.

    Science.gov (United States)

    Navarro-Ortega, Alícia; Acuña, Vicenç; Bellin, Alberto; Burek, Peter; Cassiani, Giorgio; Choukr-Allah, Redouane; Dolédec, Sylvain; Elosegi, Arturo; Ferrari, Federico; Ginebreda, Antoni; Grathwohl, Peter; Jones, Colin; Rault, Philippe Ker; Kok, Kasper; Koundouri, Phoebe; Ludwig, Ralf Peter; Merz, Ralf; Milacic, Radmila; Muñoz, Isabel; Nikulin, Grigory; Paniconi, Claudio; Paunović, Momir; Petrovic, Mira; Sabater, Laia; Sabaterb, Sergi; Skoulikidis, Nikolaos Th; Slob, Adriaan; Teutsch, Georg; Voulvoulis, Nikolaos; Barceló, Damià

    2015-01-15

    Water scarcity is a serious environmental problem in many European regions, and will likely increase in the near future as a consequence of increased abstraction and climate change. Water scarcity exacerbates the effects of multiple stressors, and thus results in decreased water quality. It impacts river ecosystems, threatens the services they provide, and it will force managers and policy-makers to change their current practices. The EU-FP7 project GLOBAQUA aims at identifying the prevalence, interaction and linkages between stressors, and to assess their effects on the chemical and ecological status of freshwater ecosystems in order to improve water management practice and policies. GLOBAQUA assembles a multidisciplinary team of 21 European plus 2 non-European scientific institutions, as well as water authorities and river basin managers. The project includes experts in hydrology, chemistry, biology, geomorphology, modelling, socio-economics, governance science, knowledge brokerage, and policy advocacy. GLOBAQUA studies six river basins (Ebro, Adige, Sava, Evrotas, Anglian and Souss Massa) affected by water scarcity, and aims to answer the following questions: how does water scarcity interact with other existing stressors in the study river basins? How will these interactions change according to the different scenarios of future global change? Which will be the foreseeable consequences for river ecosystems? How will these in turn affect the services the ecosystems provide? How should management and policies be adapted to minimise the ecological, economic and societal consequences? These questions will be approached by combining data-mining, field- and laboratory-based research, and modelling. Here, we outline the general structure of the project and the activities to be conducted within the fourteen work-packages of GLOBAQUA.

  2. Models for transport and fate of carbon, nutrients and point source released radionuclides to an aquatic ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda [Stockholm Univ. (Sweden). Dept. of Systems Ecology; Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2004-09-01

    In this report three ecosystem models are described in terms of structure, initial data, and results. All models are dynamic, mass-balanced and describe the transport and fate of elements in an open aquatic ecosystem. The models are based on ecologically sound principles, provide model results with high resolution and transparency, and are constrained by the nutrient dynamics of the ecosystem itself. The processes driving the transport in all the models are both the biological processes such as primary production, consumption, respiration and excretion, and abiotic e.g. water exchange and air-sea exchange. The first model, the CNP-model, describes the distribution and fluxes of carbon and nutrients for the coastal ecosystem off Forsmark. The second model, the C-14 model, is an extension of the CNP-model and describes the transport and distribution of hypothetically released C-14 from the underground repository SFR-1 to the ecosystem above. The third model, the RN-model, is a generic radionuclide flow model that models the transport and distribution of radionuclides other than C-14 hypothetically discharged to the ecosystem. The model also analyses the importance of some radionuclide specific mechanisms for the radionuclide flow. The generic radionuclide model is also based on the CNP-model, but has radionuclide specific mechanisms connected to each compartment.

  3. Trophic transfer of mercury and methylmercury in an aquatic ecosystem impacted by municipal sewage effluents in Beijing, China.

    Science.gov (United States)

    Fu, Jianjie; Wang, Yawei; Zhou, Qunfang; Jiang, Guibin

    2010-01-01

    Gaobeidian Lake, located in Beijing, China, serves as a recipient lake for effluents from a large municipal sewage treatment plant (MSTP). In order to evaluate the effects of discharging MSTP effluent on the mercury contamination of the local aquatic ecosystem, sediment cores, water, plankton, fish, and turtle samples were collected from Gaobeidian Lake for mercury speciation analysis. High concentrations of total mercury (T-Hg) were detected in sediment cores (5.24-17.0 microg/g dry weight (dw), average: 10.1 microg/g). The ratio of methylmercury (MeHg) to T-Hg was less than 0.3% in sediments and ranged from 35% to 76% in biota samples. The highest level of T-Hg and MeHg were found in aquatic bryophyte and crucian carp (3673 and 437 ng/g dw, respectively). The relative contents of MeHg were significantly correlated with trophic levels (R2 = 0.5506, p < 0.001), which confirmed that MeHg can be bio-transferred and biomagnified via food chain in this aquatic ecosystem.

  4. Mycobacterium ulcerans dynamics in aquatic ecosystems are driven by a complex interplay of abiotic and biotic factors.

    Science.gov (United States)

    Garchitorena, Andrés; Guégan, Jean-François; Léger, Lucas; Eyangoh, Sara; Marsollier, Laurent; Roche, Benjamin

    2015-01-01

    Host-parasite interactions are often embedded within complex host communities and can be influenced by a variety of environmental factors, such as seasonal variations in climate or abiotic conditions in water and soil, which confounds our understanding of the main drivers of many multi-host pathogens. Here, we take advantage of a combination of large environmental data sets on Mycobacterium ulcerans (MU), an environmentally persistent microorganism associated to freshwater ecosystems and present in a large variety of aquatic hosts, to characterize abiotic and biotic factors driving the dynamics of this pathogen in two regions of Cameroon. We find that MU dynamics are largely driven by seasonal climatic factors and certain physico-chemical conditions in stagnant and slow-flowing ecosystems, with an important role of pH as limiting factor. Furthermore, water conditions can modify the effect of abundance and diversity of aquatic organisms on MU dynamics, which suggests a different contribution of two MU transmission routes for aquatic hosts (trophic vs environmental transmission) depending on local abiotic factors.

  5. Water treatment by aquatic ecosystem: Nutrient removal by reservoirs and flooded fields

    Science.gov (United States)

    Reddy, K. R.; Sacco, P. D.; Graetz, D. A.; Campbell, K. L.; Sinclair, L. R.

    1982-05-01

    Potential use of reservoirs and flooded fields stocked with aquatic plants for reduction of the nutrient levels of organic soil drainage water was evaluated. The treatment systems include 1) a large single reservoir (R1) stocked with waterhyacinth ( Eichhornia crassipes), elodea ( Egeria densa), and cattails ( Typha sp.) in series; 2) three small reservoirs in series with waterhyacinth (R2), elodea (R3), and cattails (R4), grown in independent reservoirs; 3) a control reservoir (R5) with no cultivated plants; 4) a large single flooded field planted to cattails; 5) three small flooded fields in a series planted to cattails; and 6) a flooded field with no cultivated plants. Drainage water was pumped daily (6 hours a day, and 6 days a week) into these systems for a period of 27 months at predetermined constant flow rates. Water samples were collected at the inlet and outlet of each treatment system and analyzed for N and P forms. The series of reservoirs stocked with aquatic plants functioned effectively in the removal of N and P from agricultural drainage water, compared to a single large reservoir. Allowing the water to flow through the reservoir stocked with waterhyacinth plants with a residence time of 3.6 days was adequate to remove about 50% of the incoming inorganic N. Allowing the water to flow through a series of two small reservoirs, R2 and R3, with a residence time of 7.3 days was necessary to remove about 60% of the incoming ortho-P. Flooded fields were effective in the removal of inorganic N, but showed poor efficiency in the removal of ortho-P.

  6. Preservation of natural aquatic ecosystems by application of bottom coal ash based bioreactor for in situ treatment of anthropogenic effluents

    Science.gov (United States)

    Anker, Y.; Nisnevitch, M.; Tal, M.; Cahan, R.; Michael, E.

    2012-12-01

    operating with initial horizontal flow and continuous vertical circulation through aeration apparatus. Along the flow path several different bio-modules are applied, the sequence consists of aerobic and anaerobic stages, as well as biomass preservation section and fine grain filtration. The pilot biofilter facility was built during the summer of 2009; the influent consisted of domestic wastewater (of the adjacent Ariel University dormitories) and also synthetic aquatic solutions equivalent to urban, industrial, and roads runoff effluents. The biofilter operation evaluation demonstrated significant decrease in pollution loads, including organic, salts and pathogens. The facility's efficiency reached approximately 90% reduction or more, allowing the release of treated runoff without limitation to natural fluvial ecosystems (according to the required regulations). The present stage in the project is implementation of the method and process by application of a full scale pilot facility at a joint between an anthropogenic drainage network, consisting of urban, industrial and motorway runoff collection systems and a typical natural Samaritan fluvial ecosystem. The purpose of the system is to treat these anthropogenic effluents prior to their release into the stream and by that to prevent the negative environmental above mentioned effects.

  7. Evaluation of the health status of a coastal ecosystem in southeast Mexico: Assessment of water quality, phytoplankton and submerged aquatic vegetation.

    Science.gov (United States)

    Herrera-Silveira, Jorge A; Morales-Ojeda, Sara M

    2009-01-01

    The coastal environment of the Yucatan Peninsula (SE, Mexico) includes a wide variety of ecosystems ranging from mangroves to coral reefs, resulting in a heterogeneous landscape. Specifically, the marine system is characterized by environmental differences which respond to regional and local forcing functions such as marine currents and groundwater discharges (GD). Such functional characteristics were used here to define four subregions across the Yucatan coast and diagnose the health status of this coastal marine ecosystem. To achieve this goal, we conducted an analysis and integration of water quality variables, an eutrophic assessment, evaluated changes in submerged aquatic vegetation (SAV), and analyzed the community structure and distribution of harmful phytoplankton. The first step was to determine the reference values for each subregion based on data previously collected from 2002 to 2006 along the coast of Yucatan, 200m offshore. The trophic index (TRIX) and Canadian index for aquatic life (CCMEWQI) were used to diagnose each subregion and then the ASSETS approach was conducted for Dzilam and Progreso, sampling localities on each end of the health status continuum (those with the best and worst conditions). Overall, results indicated that the marine coastal ecosystem of Yucatan is in good condition; however, differences were observed between subregions that can be attributed to local forcing functions and human impacts. Specifically, the central region (zone HZII, Progreso-Telchac) showed symptoms of initial eutrophication due to nutrient inputs from human activities. The eastern region (zone HZ III, Dzilam-Las Bocas) showed a meso-eutrophic condition linked to natural groundwater discharges, while the other two subregions western (zone HZI Celestun-Palmar) and caribbean (zone HZ IV Ria Lagartos-El Cuyo) exhibited symptoms of oligo-mesotrophic condition. These findings may be considered baseline information for coastal ecosystem monitoring programs in

  8. Formation, transformation and transport of black carbon (charcoal) in terrestrial and aquatic ecosystems.

    Science.gov (United States)

    Forbes, M S; Raison, R J; Skjemstad, J O

    2006-10-15

    Black carbon (BC) is ubiquitous in terrestrial environments and its unique physical and chemical properties suggest that it may play an important role in the global carbon budget (GCB). A critical issue is whether the global production of BC results in significant amounts of carbon (C) being removed from the short-term bio-atmospheric carbon cycle and transferred to the long-term geological carbon cycle. Several dozen field and laboratory based studies of BC formation during the burning of biomass have been documented. Findings are difficult to interpret because they have been expressed in an inconsistent manner, and because different physical and chemical methods have been used to derive them. High error terms documented in many of these studies also highlight the problems associated with the quantification of the amount of biomass C consumed in fire, the amount of residue produced and the constituents of that residue. To be able to estimate the potential for BC as a carbon sink, issues regarding its definition, the methods used in its identification and measurement, and the way it is expressed in relation to other components of the carbon cycle need to be addressed. This paper presents BC data in a standard way; BC production as a percentage of the amount of C consumed by fire (BC/CC), which can be readily integrated into a larger carbon budget. Results from previous studies and new data from Australian ecosystems were recalculated in this way. As part of this process, several BC estimates derived solely from physical methods were discarded, based on their inability to accurately identify and quantify the BC component of the post-fire residue. Instead, more focus was placed on BC estimates obtained by chemical methods. This recalculated data lowered the estimate for BC formation in forest fires from 4% to 5% to <3% BC/CC. For savannah and grassland fires a value of <3% is consistent with reported data, but considerable variation among estimates remains. An

  9. Relevance of risk predictions derived from a chronic species sensitivity distribution with cadmium to aquatic populations and ecosystems

    Science.gov (United States)

    Mebane, C.A.

    2010-01-01

    Criteria to protect aquatic life are intended to protect diverse ecosystems, but in practice are usually developed from compilations of single-species toxicity tests using standard test organisms that were tested in laboratory environments. Species sensitivity distributions (SSDs) developed from these compilations are extrapolated to set aquatic ecosystem criteria. The protectiveness of the approach was critically reviewed with a chronic SSD for cadmium comprising 27 species within 21 genera. Within the data set, one genus had lower cadmium effects concentrations than the SSD fifth percentile-based criterion, so in theory this genus, the amphipod Hyalella, could be lost or at least allowed some level of harm by this criteria approach. However, population matrix modeling projected only slightly increased extinction risks for a temperate Hyalella population under scenarios similar to the SSD fifth percentile criterion. The criterion value was further compared to cadmium effects concentrations in ecosystem experiments and field studies. Generally, few adverse effects were inferred from ecosystem experiments at concentrations less than the SSD fifth percentile criterion. Exceptions were behavioral impairments in simplified food web studies. No adverse effects were apparent in field studies under conditions that seldom exceeded the criterion. At concentrations greater than the SSD fifth percentile, the magnitudes of adverse effects in the field studies were roughly proportional to the laboratory-based fraction of species with adverse effects in the SSD. Overall, the modeling and field validation comparisons of the chronic criterion values generally supported the relevance and protectiveness of the SSD fifth percentile approach with cadmium. ?? 2009 Society for Risk Analysis.

  10. Modification of a fire drought index for tropical wetland ecosystems by including water table depth

    NARCIS (Netherlands)

    Taufik, Muh; Setiawan, B.I.; Lanen, van H.A.J.

    2015-01-01

    In this paper, we discuss how an existing empirical drought index, i.e. the Keetch-Byram Drought Index (KBDI) that is commonly used for assessing forest fire danger, has been adjusted and modified for improved use in tropical wetland ecosystems. The improvement included: (i) adjustment of the dro

  11. Wetland-stream ecosystems of the western Kentucky coalfield: environmental disturbance and the shaping of aquatic community structure

    Energy Technology Data Exchange (ETDEWEB)

    Hill, P.L. Jr.

    1983-01-01

    The effects of surface mining effluents of the shaping of aquatic community structure in wetland-stream ecosystems of the western Kentucky coalfield were examined. Three variously impacted drainage systems were utilized for the investigation of cause-and-effect relationships. Clear Creek wetland-stream ecosystem had a uniformly low pH, high conductivity and high dissolved minerals load linked to the oozing of old, unreclaimed surface mine spoils. Cypress Creek wetland-stream ecosystem exhibited a slug-pulsing of mine drainage effluents tied to active surface mining limited to the headwaters region. Henderson Sloughs-Pond Creek wetland-stream ecosystem had no mining impact and was utilized as a comparison site. Macroinvertebrate taxa and diversity were considerably lowered in the systems receiving mine drainage. The Shannon-Weaver diversity index (H) was 0.61 for Clear Creek, 1.80 for Cypress Creek and 2.01 for Henderson Sloughs. Large numbers of chironomid larvae dominated the benthic community of Clear Creek while mayflies, caddisflies and crustaceans were the major components of the Cypress Creek community. Henderson Sloughs-Pond Creek had an even more diverse community of mayflies, caddisflies, crustaceans, molluscs and odonates. Fishes followed the same general trend, being almost absent in Clear Creek (H - 0.47), slightly depressed in Cypress Creek (H = 1.74) and generally diverse in Henderson Sloughs (H = 2.37).

  12. Exploring new Routes for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with 31P NMR

    Science.gov (United States)

    Vestergren, Johan; Persson, Per; Sundman, Annelie; Ilstedt, Ulrik; Giesler, Reiner; Schleucher, Jürgen; Gröbner, Gerhard

    2014-05-01

    Phosphorus (P) is the primary growth-limiting nutrient in some of the world's biomes. Rock phosphate is a non-renewable resource and the major source of agricultural fertilizers. Predictions of P consumption indicate that rock phosphate mining may peak within 35 years, with severe impacts on worldwide food production1. Organic P compounds constitute a major fraction of soil P, but little is known about the dynamics and bioavailability of organic P species. Our aim is to develop new liquid and solid state 31P-NMR (nuclear magnetic resonance) techniques to identify P-species in water and soils; information required for correlating P speciation with plant and soil processes2, and eventually to improve P use. Soil organic P is frequently extracted using NaOH/EDTA, followed by characterization of the extract by solution 31P-NMR. However, the obtained NMR spectra usually have poor resolution due to line broadening caused by the presence of paramagnetic ions. Therefore, we successfully developed an approach to avoid paramagnetic line broadening by precipitation of metal sulfides. Sulfide precipitation dramatically reduces NMR line widths for soil extracts, without affecting P-composition. The resulting highly improved resolution allowed us to apply for the first time 2D 1H,31P-NMR methods to identify different P monoesters in spectral regions which are extremely crowded in 1D NMR spectra.3 By exploiting 2D 1H-31P NMR spectra of soil extracts we were able to unambiguously identify individual organic P species by combining 31P and 1H chemical shifts and coupling constants. This approach is even suitable for a structural characterization of unknown P-components and for tracing degradation pathways between diesters and monoesters3,4.Currently we apply our approach on boreal4 and tropical soils with focus on Burkina Faso. In addition we also monitor P-species in aqueos ecosystems. For this purpose stream water from the Krycklan catchment in northern Sweden5 has been used to

  13. Organization of vegetation cover of aquatic ecosystems at Borodinskiy opencast coal mine dumps (Kansk forest-steppe, Eastern Siberia

    Directory of Open Access Journals (Sweden)

    D. Yu. Efimov

    2016-04-01

    Full Text Available The paper present the results of study of the floristic composition and importance of species of aquatic ecosystems on different types of technogenic surfaces of the Borodino coal mine and assessment of the impact of local factors on the structure and the dynamics of vegetation. The list of plant taxa containing 91 species of higher plants and 3 cha-rophytes. The largest amount of macrophytes species are Elodea canadensis Michx., Eleocharis palustris (L. Roem. & Schult., Hydrocharis morsus-ranae L., Potamogeton alpinus Balb., P. perfoliatus L., Sparganium emersum Rehm., Spirodela polyrhiza (L. Schleid., Typha latifolia L., Warnstorfia fluitans (Hedw. Loeske, Chara contraria A. Braun ex Kutz., the basis (up to 67.6‒70.9 % of vegetation mosaic of aquatic systems and differentiate its structure post-technogenic landscape. Sorensen index (QS = 0.63‒0.71 and Spearman rank correlation coefficient (rs = 0.29‒0.62, p < 0.01 values showed the greatest similarity between the species composition of the aquatic complexes arising on mineral surfaces planned dumps. The low level of similarity (QS = 0.13‒0.45; rs = 0.25‒0.34, p < 0.05 in spe-cies composition is typical fir ponds and wetlands formed around the perimeter of the heaps along the erosion of slopes. Non-parametric analysis of variance showed a statistically significant (p < 0.001 differentiation of the species composition of the variables values of the analyzed environmental factors: the direction of reclamation, type and age of geomorphic surfaces dumps. Aquatic complexes significantly complement and enrich the mosaic of man-made landscape of the Borodino coal mine, the potential of their diversity should be taken into account when developing plans and strategies for reclamation of disturbed areas.

  14. Project AProWa: a national view on managing trade-offs between agricultural production and conservation of aquatic ecosystems

    Science.gov (United States)

    Dietzel, Anne; Rahn, Eric; Stamm, Christian

    2014-05-01

    Swiss agriculture is legally committed to fulfill several, partially conflicting goals such as agricultural production on the one hand and the conservation of natural resources on the other hand. In the context of the research project AProWa ("Agricultural Production and Water"), the relationships between the production aspect and the conservation of aquatic ecosystems is analyzed with a holistic approach. Agricultural production and the protection of water resources have high potential for conflicts: Farmers use ground and surface water to irrigate their fields. On the other hand, drainage systems enable the production on otherwise unfavorably wet soils. These in turn often affect ground water recharge and divert precipitation directly into surface waters, which changes their hydrological regime. Typically, drainage systems also elevate the input of nutrients and pesticides into the water bodies. In general, applied fertilizers, plant protection products, veterinary drugs and phytohormones of cultivated plants are introduced into the ground and surface waters through different processes such as drift, leaching, runoff, preferential flow or erosion. They influence the nutrient cycles and ecological health of aquatic systems. The nutrient and pesticide loss processes themselves can be altered by tillage operations and other agricultural practices. Furthermore, the competition for space can lead to additional conflicts between agriculture and the protection of aquatic ecosystems. For example, channelized or otherwise morphologically changed rivers do not have a natural discharge pattern and are often not suitable for the local flora and fauna; but naturally meandering rivers need space that cannot be used for agriculture. In a highly industrialized and densely populated country like Switzerland, all these potential conflicts are of importance. Although it is typically seen as a water-rich country, local and seasonal overexploitation of rivers through water extraction

  15. 三峡工程对水环境与水生态的影响及保护对策%Impacts of Three Gorges Project on water environment and aquatic ecosystem and protective measures

    Institute of Scientific and Technical Information of China (English)

    邹家祥; 翟红娟

    2016-01-01

    介绍三峡工程水环境与水生态现状,分析三峡工程对库区及坝下水文情势、水质、库区及支流富营养化等水环境的影响,以及工程运行对水生态系统、饵料生物、鱼类及珍稀水生动物等水生态的影响,提出优化水库调度、加强城镇生活污水处理、工业废水防治、农村面源治理、饮用水源地保护等水环境保护对策,以及开展栖息地保护、物种保护、人工增殖放流、生态调度等水生生态保护对策。%This paper introduces the water environmental and aquatic ecological status of the Three Gorges Project. The impacts of the project on the aquatic environment, involving hydrological regimes, water quality, reservoir eutrophication, and water blooms in the tributaries, are analyzed. The project ’ s impacts on aquatic ecology, including the aquatic ecosystem, food organisms, fish species, and rare aquatic animals, are also analyzed. Several measures are proposed to protect the water environment, including optimization of reservoir regulation, urban sewage treatment, industrial waste water control, rural non-point source pollution control, and drinking water source protection. For the protection of the aquatic ecosystem, some measures are put forward, including habitat conservation, species conservation, artificial enhancement and release of fish, and ecological reservoir regulation.

  16. Spawner-recruit relationships and fish stock carrying capacity in aquatic ecosystems

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Myers, R.A.; Bowen, K.G.

    2003-01-01

    Few marine ecologists have addressed important questions about the relative productivity and carrying capacity of different ecosystems required to support fish populations. Whereas many researchers have investigated interannual variability in recruitment within a stock, we asked whether...

  17. Diversity and distribution of diapausing aquatic invertebrates in inland wetlands: An ecosystem conservation viewpoint

    DEFF Research Database (Denmark)

    Muñoz, Joaquin

    2010-01-01

    processes determining the biogeography of cosmopolitan species are needed. Further knowledge of these issues should provide invaluable information allowing development of appropriate conservation management policies for inland waters across entire ecosystems, landscapes, and geographic regions....

  18. Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

    Science.gov (United States)

    Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Judd, Chaeli; Woodruff, Dana; Ellis, Jean; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

    2012-01-01

    Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

  19. The mysteriously variable half-life of dissolved organic matter in aquatic ecosystems: artefact or insight?

    Science.gov (United States)

    Evans, Chris; Fovet, Ophelie; Jones, Tim; Jones, Davey; Moldan, Filip; Futter, Martyn

    2016-04-01

    Dissolved organic matter (DOM) fluxes from land to water represent an important loss term in the terrestrial carbon balance, a major pathway in the global carbon cycle, a significant influence on aquatic light, nutrient and energy regimes, and an important concern for drinking water production. Although freshwaters are now recognised as zones of active carbon cycling, rather than passive conduits for carbon transport, evidence regarding the magnitude of, and controls on, DOM cycling in aquatic systems is incomplete and in some cases seemingly contradictory, with DOM 'half-lives' ranging from a few days to many years. Bringing together experimental, isotopic, catchment mass balance and modelling data, we suggest that apparently conflicting results can be reconciled through understanding of differences in: i) the terrestrial sources of DOM within heterogeneous landscapes, and consequent differences in its reactivity and stoichiometry; ii) experimental methodologies (i.e. which reactions are actually being measured), and iii) the extent of prior transformation of DOM upstream of the point of study. We argue that rapid photo-degradation, particularly of peat-derived DOM, is a key process in headwaters, whilst apparently slow DOM turnover in downstream, agriculturally-influenced lakes and rivers can partly be explained by the offsetting effect of in situ DOM production. This production appears to be strongly constrained by nutrient supply, thus linking DOM turnover and composition to the supply of inorganic nutrient inputs from diffuse agricultural pollution, and also providing a possible mechanistic link between aquatic DOM production and terrestrial DOM breakdown via the mineralisation and re-assimilation of organic nutrients. A more complete conceptual understanding of these interlinked processes will provide an improved understanding of the sources and fate of aquatic DOM, its role in the global carbon cycle, and the impact of anthropogenic activities, for example

  20. Developing a participatory process to include ecosystem services in landscape planing

    Science.gov (United States)

    Onaindia, Miren; Palacios-Agundez, Igone; Rodríguez-Loinaz, Gloria; Peña, Lorena; Madariaga, Iosu; Ametzaga, Ibone

    2015-04-01

    This work develops an approach that integrates scientific knowledge on ecosystem services and stakeholders demands to get guidelines for landscape planning strategies in the region of Biscay (Basque Country, northern Spain). In the conducted participatory process, forest multi-functionality was considered as a practicable good alternative. This process identified also a knowledge gap on the synergies and trade-offs between biodiversity, timber production and carbon storage, guiding the directions of the research actions. The results from developed spatial analysis converged with those from the participatory process in the adequacy of promoting, where possible and appropriate, natural forest ecosystems restoration. The ongoing stepwise learning strategy is already showing its effectiveness for decision making, with concrete examples of how the results obtained with the applied approach are being included in planning and decision-making processes.

  1. Two prototype tools for assessing good environmental/ecological status (GES) in aquatic ecosystems – DEVOTES and WATERS

    DEFF Research Database (Denmark)

    Murray, Ciarán; Carstensen, Jacob; Andersen, Jesper

    2015-01-01

    We present two prototype tools for assessment of GES (good ecological status and good environmental status) in aquatic ecosystems: the DEVOTES biodiversity assessment tool (for the MSFD) and the WATERS ecological status assessment tool (for the WFD). Both tools are multi-metric indicator......-based tools, which classify ecological/environmental status in two classes (good or not good) and five classes (High, Good, Moderate, Poor or Bad) by comparing observed indicator values with specified status classification boundaries. Assessments are made for geographical entities (“sectors” in DEVOTES...... / “waterbodies” in WATERS) resulting in both an overall status for the geographical entity as well as classifications within indicator groups. Both tools are Excel-based and share many similarities. Whilst the WATERS tool performs assessments for a simple “flat” set of waterbodies, the DEVOTES tools allows...

  2. Genetically modified crops and aquatic ecosystems: considerations for environmental risk assessment and non-target organism testing.

    Science.gov (United States)

    Carstens, Keri; Anderson, Jennifer; Bachman, Pamela; De Schrijver, Adinda; Dively, Galen; Federici, Brian; Hamer, Mick; Gielkens, Marco; Jensen, Peter; Lamp, William; Rauschen, Stefan; Ridley, Geoff; Romeis, Jörg; Waggoner, Annabel

    2012-08-01

    Environmental risk assessments (ERA) support regulatory decisions for the commercial cultivation of genetically modified (GM) crops. The ERA for terrestrial agroecosystems is well-developed, whereas guidance for ERA of GM crops in aquatic ecosystems is not as well-defined. The purpose of this document is to demonstrate how comprehensive problem formulation can be used to develop a conceptual model and to identify potential exposure pathways, using Bacillus thuringiensis (Bt) maize as a case study. Within problem formulation, the insecticidal trait, the crop, the receiving environment, and protection goals were characterized, and a conceptual model was developed to identify routes through which aquatic organisms may be exposed to insecticidal proteins in maize tissue. Following a tiered approach for exposure assessment, worst-case exposures were estimated using standardized models, and factors mitigating exposure were described. Based on exposure estimates, shredders were identified as the functional group most likely to be exposed to insecticidal proteins. However, even using worst-case assumptions, the exposure of shredders to Bt maize was low and studies supporting the current risk assessments were deemed adequate. Determining if early tier toxicity studies are necessary to inform the risk assessment for a specific GM crop should be done on a case by case basis, and should be guided by thorough problem formulation and exposure assessment. The processes used to develop the Bt maize case study are intended to serve as a model for performing risk assessments on future traits and crops.

  3. Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Houserova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic)]. E-mail: kuban@mendelu.cz; Kracmar, Stanislav [Department of Animal Nutrition, Mendel University of Agriculture and Forestry, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Sitko, Jilji [Commenius Museum, Moravian Ornithological Station, Horni nam. 1, Prerov CZ-751 52 (Czech Republic)

    2007-01-15

    Total mercury and mercury species (methylmercury-MeHg, inorganic mercury - Hg{sup 2+}) were determined in the aquatic ecosystem Zahlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species - cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F {sub 4.6} = 56.71, P < 10{sup -5}). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg. - The distribution of the mercury species among the organs of the individual birds is discussed.

  4. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    Energy Technology Data Exchange (ETDEWEB)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    1996-12-31

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS.

  5. Reviews and syntheses : Effects of permafrost thaw on Arctic aquatic ecosystems

    NARCIS (Netherlands)

    Vonk, J. E.; Tank, S. E.; Bowden, W. B.; Laurion, I.; Vincent, W. F.; Alekseychik, P.; Amyot, M.; Billet, M. F.; Canário, J.; Cory, R. M.; Deshpande, B. N.; Helbig, M.; Jammet, M.; Karlsson, J.; Larouche, J.; Macmillan, G.; Rautio, M.; Walter Anthony, K. M.; Wickland, K. P.

    2015-01-01

    The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current st

  6. Effect of pesticides used in banana and pineapple plantations on aquatic ecosystems in Costa Rica

    NARCIS (Netherlands)

    Diepens, N.J.; Pfennig, S.; Brink, van den P.J.; Gunnarsson, J.S.; Ruepert, C.; Castillo, L.

    2014-01-01

    Current knowledge on fate and effect of agricultural pesticides comes is mainly from temperate ecosystems. More studies are needed in tropical systems in order to assess contamination risks to nontarget endemic tropical species from the extensive use of pesticides e.g. in banana and pineapple planta

  7. Climate-driven changes in the ecological stoichiometry of aquatic ecosystems

    NARCIS (Netherlands)

    van de Waal, D.B.; Verschoor, A.M.; Verspagen, J.M.H.; van Donk, E.; Huisman, J.

    2010-01-01

    Advances in ecological stoichiometry, a rapidly expanding research field investigating the elemental composition of organisms and their environment, have shed new light on the impacts of climate change on freshwater and marine ecosystems. Current changes in the Earth's climate alter the availability

  8. Social Values for Ecosystem Services (SolVES): using GIS to include social values information in ecosystem services assessments

    Science.gov (United States)

    Sherrouse, B.C.; Semmens, D.J.

    2010-01-01

    Ecosystem services can be defined in various ways; simply put, they are the benefits provided by nature, which contribute to human well-being. These benefits can range from tangible products such as food and fresh water to cultural services such as recreation and esthetics. As the use of these benefits continues to increase, additional pressures are placed on the natural ecosystems providing them. This makes it all the more important when assessing possible tradeoffs among ecosystem services to consider the human attitudes and preferences that express underlying social values associated with their benefits. While some of these values can be accounted for through economic markets, other values can be more difficult to quantify, and attaching dollar amounts to them may not be very useful in all cases. Regardless of the processes or units used for quantifying such values, the ability to map them across the landscape and relate them to the ecosystem services to which they are attributed is necessary for effective assessments. To address some of the needs associated with quantifying and mapping social values for inclusion in ecosystem services assessments, scientists at the Rocky Mountain Geographic Science Center (RMGSC), in collaboration with Colorado State University, have developed a public domain tool, Social Values for Ecosystem Services (SolVES). SolVES is a geographic information system (GIS) application designed to use data from public attitude and preference surveys to assess, map, and quantify social values for ecosystem services. SolVES calculates and maps a 10-point Value Index representing the relative perceived social values of ecosystem services such as recreation and biodiversity for various groups of ecosystem stakeholders. SolVES output can also be used to identify and model relationships between social values and physical characteristics of the underlying landscape. These relationships can then be used to generate predicted Value Index maps for areas

  9. Survey of Methods to Assess the Toxicological Impact of Hazardous Waste Disposal Sites on Aquatic Ecosystems

    Science.gov (United States)

    1989-07-01

    fluorescence, is directly related to increased toxic effect. Therefore, the inhibition index can be used as a bioindicator of the health of the algal...1988). This bioassay uses starlings as bioindicators of toxicological effects by establishing a quadrat of nest boxes to create a gradient of exposure...single species populations in benthos of mesocosms and coastal ecosystems." In: Concepts in Marine Pollution Measurements. H.H. White (Ed.), Maryland Sea

  10. Element transport in aquatic ecosystems – Modelling general and element-specific mechanisms

    OpenAIRE

    Konovalenko, Lena

    2014-01-01

    Radionuclides are widely used in energy production and medical, military and industrial applications. Thus, understanding the behaviour of radionuclides which have been or may be released into ecosystems is important for human and environmental risk assessment. Modelling of radionuclides or their stable element analogues is the only tool that can predict the consequences of accidental release. In this thesis, two dynamic stochastic compartment models for radionuclide/element transfer in a mar...

  11. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, C.L.

    1994-09-01

    As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentration factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms.

  12. The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

    DEFF Research Database (Denmark)

    Douglas, Thomas A.; Loseto, Lisa L.; MacDonald, Robie W.

    2012-01-01

    This review is the result of a series of multidisciplinary meetings organised by the Arctic Monitoring and Assessment Programme as part of their 2011 Assessment ‘Mercury in the Arctic’. This paper presents the state-of-the-art knowledge on the environmental fate of mercury following its entry...... ecosystem trophic processes and biologic Hg levels. We examine whether atmospheric mercury depletion events (AMDEs) contribute to increased Hg levels in Arctic biota and provide information on the links between organic carbon and Hg speciation, dynamics and bioavailability. Long-term sequestration of Hg...

  13. Spatial and temporal controls on Alnus-derived nutrients and stream stoichiometry: Implications for aquatic ecosystem productivity

    Science.gov (United States)

    Devotta, D.; Fraterrigo, J.; Walsh, P.; Hu, F.

    2015-12-01

    Predicting how nutrient fluxes that cross ecosystem boundaries will respond to future climate change is one of the greatest challenges for ecology in the 21st century. In southwestern (SW) Alaska, Pacific salmon (Oncorhynchus spp.) and nitrogen (N)-fixation by alder (Alnus spp.) provide key nutrient subsidies to freshwater systems. The importance of alder-derived nutrients (ADN) to aquatic systems will increase as alder cover expands under climate warming and salmon harvesting reduces marine-derived nutrients. We investigate broad-scale spatial and temporal drivers of ADN and stream N:P in 26 streams in SW Alaska. Alder cover and watershed features were measured using satellite images and topographic maps in ArcGIS. Stream water samples were collected in each spring and summer from 2010-2013 and analyzed for dissolved N and total phosphorus (TP). We obtained annual growing season length (AGSL) and sum of growing degree days (GDD) data from weather stations. Elevation was inversely related to alder cover, stream N, and N:P (ρ=-0.802, -0.65, and -0.71 resp., pADN export. Higher P was associated with lower temperatures, possibly reflecting reduced P demand under low rates of metabolic activity. Structural equation modeling revealed significant causal relationships among elevation, alder cover, and stream N:P across multiple years (r2=0.94, X2=742.8, df=9, pADN fluxes and stream N:P than temporal variation in growing season conditions. Therefore, the aquatic productivity of streams at low elevations that receive large amounts of ADN will be most resilient to climate change.

  14. The Economic Value of the Greater Montreal Blue Network (Quebec, Canada): A Contingent Choice Study Using Real Projects to Estimate Non-Market Aquatic Ecosystem Services Benefits.

    Science.gov (United States)

    Poder, Thomas G; Dupras, Jérôme; Fetue Ndefo, Franck; He, Jie

    2016-01-01

    This study used a contingent choice method to determine the economic value of improving various ecosystem services (ESs) of the Blue Network of Greater Montreal (Quebec, Canada). Three real projects were used and the evaluation focused on six ESs that are related to freshwater aquatic ecosystems: biodiversity, water quality, carbon sequestration, recreational activities, landscape aesthetics and education services. We also estimated the value associated with the superficies of restored sites. We calculated the monetary value that a household would be willing to pay for each additional qualitative or quantitative unit of different ESs, and these marginal values range from $0.11 to $15.39 per household per unit. Thus, under certain assumptions, we determined the monetary values that all Quebec households would allocate to improve each ES in Greater Montreal by one unit. The most valued ES was water quality ($13.5 million), followed by education services ($10.7 million), recreational activities ($8.9 million), landscape aesthetics ($4.1 million), biodiversity ($1.2 million), and carbon sequestration ($0.1 million). Our results ascribe monetary values to improved (or degraded) aquatic ecosystems in the Blue Network of Greater Montreal, but can also enhance economic analyses of various aquatic ecosystem restoration and management projects.

  15. The Economic Value of the Greater Montreal Blue Network (Quebec, Canada): A Contingent Choice Study Using Real Projects to Estimate Non-Market Aquatic Ecosystem Services Benefits

    Science.gov (United States)

    Dupras, Jérôme; Fetue Ndefo, Franck; He, Jie

    2016-01-01

    This study used a contingent choice method to determine the economic value of improving various ecosystem services (ESs) of the Blue Network of Greater Montreal (Quebec, Canada). Three real projects were used and the evaluation focused on six ESs that are related to freshwater aquatic ecosystems: biodiversity, water quality, carbon sequestration, recreational activities, landscape aesthetics and education services. We also estimated the value associated with the superficies of restored sites. We calculated the monetary value that a household would be willing to pay for each additional qualitative or quantitative unit of different ESs, and these marginal values range from $0.11 to $15.39 per household per unit. Thus, under certain assumptions, we determined the monetary values that all Quebec households would allocate to improve each ES in Greater Montreal by one unit. The most valued ES was water quality ($13.5 million), followed by education services ($10.7 million), recreational activities ($8.9 million), landscape aesthetics ($4.1 million), biodiversity ($1.2 million), and carbon sequestration ($0.1 million). Our results ascribe monetary values to improved (or degraded) aquatic ecosystems in the Blue Network of Greater Montreal, but can also enhance economic analyses of various aquatic ecosystem restoration and management projects. PMID:27513558

  16. Interactive effects of phosphorus and copper on Hyalella azteca via periphyton in aquatic ecosystems.

    Science.gov (United States)

    Li, Miling; Costello, David M; Burton, G Allen

    2012-09-01

    This research examined the interaction between dissolved copper and phosphorus, with respect to their effects on the freshwater amphipod Hyalella azteca feeding on periphyton. Field-collected periphyton communities were exposed to different nutrient and metal conditions in indoor recirculating streams. H. azteca were then exposed to water and periphyton from these streams. There was rapid Cu accumulation by periphyton but the total Cu concentration of periphyton was not directly related to dissolved P. In terms of H. azteca growth, an interactive effect was found between Cu and P as growth was reduced more than expected in the low Cu-high P treatment. Our data suggest that eutrophic conditions result in greater Cu toxicity to benthic macroinvertebrates at lower metal concentrations, likely due to higher assimilation efficiency of dietary Cu from periphyton incubated under eutrophic conditions. These results imply that non-additive interactions between multiple stressors may cause ecosystem effects as detected in standard laboratory bioassays conducted under controlled conditions.

  17. Including sugar cane in the agro-ecosystem model ORCHIDEE-STICS

    Science.gov (United States)

    Valade, A.; Vuichard, N.; Ciais, P.; Viovy, N.

    2010-12-01

    With 4 million ha currently grown for ethanol in Brazil only, approximately half the global bioethanol production in 2005 (Smeets 2008), and a devoted land area expected to expand globally in the years to come, sugar cane is at the heart of the biofuel debate. Indeed, ethanol made from biomass is currently the most widespread option for alternative transportation fuels. It was originally promoted as a carbon neutral energy resource that could bring energy independence to countries and local opportunities to farmers, until attention was drawn to its environmental and socio-economical drawbacks. It is still not clear to which extent it is a solution or a contributor to climate change mitigation. Dynamic Global Vegetation models can help address these issues and quantify the potential impacts of biofuels on ecosystems at scales ranging from on-site to global. The global agro-ecosystem model ORCHIDEE describes water, carbon and energy exchanges at the soil-atmosphere interface for a limited number of natural and agricultural vegetation types. In order to integrate agricultural management to the simulations and to capture more accurately the specificity of crops' phenology, ORCHIDEE has been coupled with the agronomical model STICS. The resulting crop-oriented vegetation model ORCHIDEE-STICS has been used so far to simulate temperate crops such as wheat, corn and soybean. As a generic ecosystem model, each grid cell can include several vegetation types with their own phenology and management practices, making it suitable to spatial simulations. Here, ORCHIDEE-STICS is altered to include sugar cane as a new agricultural Plant functional Type, implemented and parametrized using the STICS approach. An on-site calibration and validation is then performed based on biomass and flux chamber measurements in several sites in Australia and variables such as LAI, dry weight, heat fluxes and respiration are used to evaluate the ability of the model to simulate the specific

  18. Polonium, uranium and plutonium radionuclides in aquatic and land ecosystem of Poland.

    Science.gov (United States)

    Skwarzec, Bogdan; Strumińska-Parulska, Dagmara I; Boryło, Alicja; Kabat, Krzysztof

    2012-01-01

    This article presents the results of study about distribution, inflow and accumulation of polonium, uranium and plutonium in aquatic and land environment of Poland and the southern Baltic Sea. Radionuclides of (210)Po, (234)U and (238)U as well as (239+240)Pu and (241)Pu are strongly accumulated in Baltic organisms and plants and transferred through the trophic chain. The values of bioconcentration factor (BCF) in Baltic plants and animals are higher for polonium and plutonium in comparison with uranium. The principal source of radionuclides in the southern Baltic Sea is their inflow with rivers. Total annual runoff of polonium, uranium and plutonium from the Vistula and the Odra as well as the Pomeranian rivers were calculated at 95 GBq of (210)Po, 750 GBq of (234+238)U and 160 MBq of (238+239+240)Pu. Seasonal and spatial variability of (210)Po, (238)U and (239+240)Pu levels in the Vistula and the Odra drainage basins were assessed by application of neural-network based classification, especially cluster analysis (CA), principal component analysis (PCA) and self-organizing maps (SOM). The result for the Vistula river indicated correlation between polonium and plutonium as well as polonium and uranium. In the Odra drainage basin, the biggest differences were observed in the case of (238)U. To assess if there are statistically significant differences in mean concentration values of (210)Po, (238)U and (239+240)Pu for the Vistula and the Odra rivers drainage basins were obtained by used of the non-parametric tests. Comparing to the Vistula catchment area, statistically differences concentration of (210)Po and (239+240)Pu in all year was observed for river samples collected on the Odra drainage basin.

  19. Impact of photochemical processing of DOC on the bacterioplankton respiratory quotient in aquatic ecosystems

    Science.gov (United States)

    Allesson, Lina; Ström, Lena; Berggren, Martin

    2016-07-01

    Many studies assume a respiratory quotient (RQ = molar ratio of CO2 produced to O2 consumed) close to 1 when calculating bacterioplankton respiration. However, evidence suggests that RQ depends on the chemical composition of the respired substrate pool that may be altered by photochemical production of oxygen-rich substrates, resulting in elevated RQs. Here we conducted a novel study of the impact of photochemical processing of dissolved organic carbon (DOC) on RQ. We monitored the bacterial RQ in bioassays of both ultraviolet light irradiated and nonirradiated humic lake water, using optic gas-pressure sensors. In the experimentally irradiated samples the average RQ value was significantly higher (3.4-3.5 [±0.4 standard error (SE)]) than that in the dark controls (1.3 [±0.1 SE]). Our results show that the RQ is systematically higher than 1 when the bacterial metabolism in large part is based on photoproducts. By assuming an RQ of 1, bacterioplankton respiration in freshwater ecosystems may be greatly underestimated.

  20. Dynamics of active pharmaceutical ingredients loads in a Swiss university hospital wastewaters and prediction of the related environmental risk for the aquatic ecosystems.

    Science.gov (United States)

    Daouk, Silwan; Chèvre, Nathalie; Vernaz, Nathalie; Widmer, Christèle; Daali, Youssef; Fleury-Souverain, Sandrine

    2016-03-15

    The wastewater contamination of a Swiss university hospital by active pharmaceutical ingredient (API) residues was evaluated with a three months monitoring campaign at the outlet of the main building. Flow-proportional samples were collected with an automatic refrigerated sampler and analyzed for 15 API, including antibiotics, analgesics, antiepileptic and anti-inflammatory drugs, by using a validated LC-MS/MS method. The metals Gd and Pt were also analyzed using ICP-MS. Measured concentrations were compared to the predicted ones calculated after the drug average consumption data obtained from the hospital pharmacy. The hospital contribution to the total urban load was calculated according to the consumption data obtained from city pharmacies. Lastly, the environmental hazard and risk quotients (RQ) related to the hospital fraction and the total urban consumption were calculated. Median concentrations of the 15 selected compounds were ranging from 0.04 to 675 μg/L, with a mean detection frequency of 84%. The ratio between predicted and measured environmental concentrations (PEC/MEC) has shown a good accuracy for 5 out of 15 compounds, revealing over- and under-estimations of the PEC model. Mean daily loads were ranging between 0.01 and 14.2g/d, with the exception of paracetamol (109.7 g/d). The hospital contribution to the total urban loads varied from 2.1 to 100% according to the compound. While taking into account dilution and removal efficiencies in wastewater treatment plant, only the hospital fraction of the antibiotics ciprofloxacin and sulfamethoxazole showed, respectively, a high (RQ>1) and moderate (RQ>0.1) risk for the aquatic ecosystems. Nevertheless, when considering the total urban consumption, 7 compounds showed potential deleterious effects on aquatic organisms (RQ>1): gabapentin, sulfamethoxazole, ciprofloxacin, piperacillin, ibuprofen, diclofenac and mefenamic acid. In order to reduce inputs of API residues originating from hospitals various

  1. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh).

    Science.gov (United States)

    Borrell, Asunción; Tornero, Victoria; Bhattacharjee, Dola; Aguilar, Alex

    2016-03-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ(15)N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health.

  2. Trace element accumulation and trophic relationships in aquatic organisms of the Sundarbans mangrove ecosystem (Bangladesh)

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, Asunción, E-mail: xonborrell@ub.edu [Department of Animal Biology, Institute of Biodiversity (IRBIO), University of Barcelona, Av. Diagonal, 643, Barcelona (Spain); Tornero, Victoria [Department of Animal Biology, Institute of Biodiversity (IRBIO), University of Barcelona, Av. Diagonal, 643, Barcelona (Spain); Bhattacharjee, Dola [Indian Institute of Science Education & Research — Kolkata, Department of Biological Sciences, Mohanpur Campus, Nadia, West Bengal (India); Aguilar, Alex [Department of Animal Biology, Institute of Biodiversity (IRBIO), University of Barcelona, Av. Diagonal, 643, Barcelona (Spain)

    2016-03-01

    The Sundarbans forest is the largest and one of the most diverse and productive mangrove ecosystems in the world. Located at the northern shoreline of the Bay of Bengal in the Indian Ocean and straddling India and Bangladesh, the mangrove forest is the result of three primary river systems that originate further north and northwest. During recent decades, the Sundarbans have been subject to increasing pollution by trace elements caused by the progressive industrialization and urbanization of the basins of these three rivers. As a consequence, animals and plants dwelling downstream in the mangroves are exposed to these pollutants in varying degrees, and may potentially affect human health when consumed. The aim of the present study was to analyse the concentrations of seven trace elements (Zn, Cu, Cr, Hg, Pb, Cd and As) in 14 different animal and plant species collected in the Sundarbans in Bangladesh to study their transfer through the food web and to determine whether their levels in edible species are acceptable for human consumption. δ{sup 15}N values were used as a proxy of the trophic level. A decrease in Zn, Cu, Pb and Cd levels was observed with increasing trophic position. Trace element concentrations measured in all organisms were, in general, lower than the concentrations obtained in other field studies conducted in the same region. When examined with respect to accepted international standards, the concentrations observed in fish and crustaceans were generally found to be safe for human consumption. However, the levels of Zn in Scylla serrata and Cr and Cd in Harpadon nehereus exceeded the proposed health advisory levels and may be of concern for human health. - Highlights: • Trace elements were determined in organisms from the Sundarbans mangrove. • The levels found were similar to those determined in wildlife from other mangroves. • Levels in three edible species were close to threshold limits for human consumption. • Except for Cr, As and Hg

  3. Managing the effects of multiple stressors on aquatic ecosystems under water scarcity

    Science.gov (United States)

    Barceló Cullerés, Damià; Ludwig, Ralf

    2015-04-01

    Water and water-related services are major components of the human wellbeing, and as such are major factors of socio-economic development in Europe; yet freshwater systems are under threat by a variety of stressors (organic and inorganic pollution, geomorphological alterations, land cover change, water abstraction, invasive species and pathogens. Some stressors, such as water scarcity, can be a stressor on its own because of its structural character, and drive the effects of other stressors. The relevance of water scarcity as a stressor is more important in semi-arid regions, such as the Mediterranean basin, which are characterized by highly variable river flows and the occurrence of low flows. This has resulted in increases in frequency and magnitude of extreme flow events. Furthermore, in other European regions such as eastern Germany, western Poland and England, water demand exceeds water availability and water scarcity has become an important management issue. Water scarcity is most commonly associated with inappropriate water management, with resulting river flow reductions. It has become one of the most important drivers of change in freshwater ecosystems. Conjoint occurrence of a myriad of stressors (chemical, geomorphological, biological) under water scarcity will produce novel and unfamiliar synergies and most likely very pronounced effects. Within this context, GLOBAQUA has assembled a multidisciplinary team of leading scientists in the fields of hydrology, chemistry, ecology, ecotoxicology, economy, sociology, engineering and modeling in order to study the interaction of multiple stressors within the frame of strong pressure on water resources. The aim is to achieve a better understanding how current management practices and policies could be improved by identifying the main drawbacks and alternatives.

  4. Nejayote produced at household level by Mayan women in Guatemala : is it a threat to aquatic ecosystems or a resource for food security?

    OpenAIRE

    Cifuentes de Gramajo, Luisa

    2011-01-01

    The aim of this study was to find out if nejayote produced at household level in Guatemala represents a threat to aquatic ecosystems and, if so, propose sustainable processing, reuse and disposal methods. First, all aspects related to nejayote production were explored. This study presents combined results from literature study on corn consumption and Guatemalan demography, a survey to Guatemalan women of all ethnical groups, nixtamalization replica and solids removal experiments and laborator...

  5. Towards Sustaining Water Resources and Aquatic Ecosystems: Forecasting Watershed Risks to Current and Future Land Use Change

    Science.gov (United States)

    Lohse, K. A.; Newburn, D.; Opperman, J. J.; Brooks, C.; Merenlender, A.

    2005-05-01

    development in a watershed significantly reduced the odds of observing low embeddedness. Our 2010 forecasts highlight the sensitivity of watersheds to small changes in exurban growth. In previously unimpaired watersheds, small increases in future exurban growth resulted in cumulative impacts on substrate quality not predicted by models lacking this land use type. Because most previous analyses have characterized land use at a resolution that cannot capture exurban development, these results suggest that many such models may be missing an important type of development that can adversely impacting aquatic ecosystems. We suggest that parcel level data may be the fundamental unit for land use change analysis because it represents the economic decision unit for land owners and resolves issues of geographical scale and boundary issues that have long hampered progress in ecological forecasting.

  6. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    Science.gov (United States)

    Fader, M.; von Bloh, W.; Shi, S.; Bondeau, A.; Cramer, W.

    2015-11-01

    In the Mediterranean region, climate and land use change are expected to impact on natural and agricultural ecosystems by warming, reduced rainfall, direct degradation of ecosystems and biodiversity loss. Human population growth and socioeconomic changes, notably on the eastern and southern shores, will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (Lund-Potsdam-Jena managed Land - LPJmL): nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural) and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development paves the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry), and opens the door for a large number of applications in the Mediterranean region, for example assessments of the consequences of land use transitions, the influence of management practices and climate change impacts.

  7. Environmental assessment of biofuel chains based on ecosystem modelling, including land-use change effects

    Science.gov (United States)

    Gabrielle, B.; Gagnaire, N.; Massad, R.; Prieur, V.; Python, Y.

    2012-04-01

    The potential greenhouse gas (GHG) savings resulting from the displacement of fossil energy sources by bioenergy mostly hinges on the uncertainty on the magnitude of nitrous oxide (N2O) emissions from arable soils occuring during feedstock production. These emissions are broadly related to fertilizer nitrogen input rates, but largely controlled by soil and climate factors which makes their estimation highly uncertain. Here, we set out to improve estimates of N2O emissions from bioenergy feedstocks by using ecosystem models and measurements and modeling of atmospheric N2O in the greater Paris (France) area. Ground fluxes were measured in two locations to assess the effect of soil type and management, crop type (including lignocellulosics such as triticale, switchgrass and miscanthus), and climate on N2O emission rates and dynamics. High-resolution maps of N2O emissions were generated over the Ile-de-France region (around Paris) with two ecosystem models using geographical databases on soils, weather data, land-use and crop management. The models were tested against ground flux measurements and the emission maps were fed into the atmospheric chemistry-transport model CHIMERE. The maps were tested by comparing the CHIMERE simulations with time series of N2O concentrations measured at various heights above the ground in two locations in 2007. The emissions of N2O, as integrated over the region, were used in a life-cycle assessment of representative biofuel pathways: bioethanol from wheat and sugar-beet (1st generation), and miscanthus (2nd generation chain); bio-diesel from oilseed rape. Effects related to direct and indirect land-use changes (in particular on soil carbon stocks) were also included in the assessment based on various land-use scenarios and literature references. The potential deployment of miscanthus was simulated by assuming it would be grown on the current sugar-beet growing area in Ile-de-France, or by converting land currently under permanent fallow

  8. SPATIAL AND MULTIVARIATE ANALYSIS OF TRACE ELEMENTS IN THE SURFACE WATER AND DEEP SEDIMENTS OF FRESH WATER AQUATIC ECOSYSTEM

    Directory of Open Access Journals (Sweden)

    Kantha Deivi Arunachalam

    2014-01-01

    Full Text Available The aim of this study was to assess the levels of various trace metals present in water and sediment of fresh water aquatic ecosystem during the post monsoon season. The study was extended to identify the trace metal contamination in the water and sediment samples collected along the shores of Lambapur and Peddagattu the tribal villages in India using an Inductively Coupled Plasma Optical Emission Spectrometer (ICPMS. The trace metal contents in water samples were copper- 24.2 to 47.5, chromium- 4.4 to 8.2, cadmium- 0.1 to 0.3, lead- 2.1 to 3.8, Nickel- 5.9 to 9.7, Zinc- 4.6 to 9.7, Manganese- 10.8 to 13.2, Iron- 52.9 to 157.2 (µg L-1 cobalt and arsenic were in BDL and the values were within the limits of Indian drinking water standards (BIS 10500: 1991. The trace metals concentration in the sediment samples ranged from (mg kg-1: Copper- 61.5 to 113.7, chromium- 138.4 to 177.5, cobalt- 33.2 to 42.7, cadmium- 1.0 to 2.1, lead- 57.9 to 103.4, Nickel- 36.1 to 56.6, Zinc- 51.2 to 102.1, Manganese- 610.8 to 1301.7 and Iron- 2.5 to 2.9%. In our study, four reliable indices such as Enrichment factor, Contamination factor, Geoaccumulation Index and Pollution Load Index were applied to estimate metal pollution and the results comparison are discussed below. The data generated were used to determine the quality of the sediments based on the enrichment factor, contamination factor and degree of contamination, geochemical index and Pollution Load Index (PLI.

  9. A Screening-Level Approach for Comparing Risks Affecting Aquatic Ecosystem Services over Socio-Environmental Gradients

    Science.gov (United States)

    Harmon, T. C.; Conde, D.; Villamizar, S. R.; Reid, B.; Escobar, J.; Rusak, J.; Hoyos, N.; Scordo, F.; Perillo, G. M.; Piccolo, M. C.; Zilio, M.; Velez, M.

    2015-12-01

    Assessing risks to aquatic ecosystems services (ES) is challenging and time-consuming, and effective strategies for prioritizing more detailed assessment efforts are needed. We propose a screening-level risk analysis (SRA) approach that scales ES risk using socioeconomic and environmental indices to capture anthropic and climatic pressures, as well as the capacity for institutional responses to those pressures. The method considers ES within a watershed context, and uses expert input to prioritize key services and the associated pressures that threaten them. The SRA approach focuses on estimating ES risk affect factors, which are the sum of the intensity factors for all hazards or pressures affecting the ES. We estimate the pressure intensity factors in a novel manner, basing them on the nation's (i) human development (proxied by Inequality-adjusted Human Development Index, IHDI), (ii) environmental regulatory and monitoring state (Environmental Performance Index, EPI) and (iii) the current level of water stress in the watershed (baseline water stress, BWS). Anthropic intensity factors for future conditions are derived from the baseline values based on the nation's 10-year trend in IHDI and EPI; ES risks in nations with stronger records of change are rewarded more/penalized less in estimates for good/poor future management scenarios. Future climatic intensity factors are tied to water stress estimates based on two general circulation model (GCM) outcomes. We demonstrate the method for an international array of six sites representing a wide range of socio-environmental settings. The outcomes illustrate novel consequences of the scaling scheme. Risk affect factors may be greater in a highly developed region under intense climatic pressure, or in less well-developed regions due to human factors (e.g., poor environmental records). As a screening-level tool, the SRA approach offers considerable promise for ES risk comparisons among watersheds and regions so that

  10. Are harmful algal blooms becoming the greatest inland water quality threat to public health and aquatic ecosystems?

    Science.gov (United States)

    Brooks, Bryan W; Lazorchak, James M; Howard, Meredith D A; Johnson, Mari-Vaughn V; Morton, Steve L; Perkins, Dawn A K; Reavie, Euan D; Scott, Geoffrey I; Smith, Stephanie A; Steevens, Jeffery A

    2016-01-01

    In this Focus article, the authors ask a seemingly simple question: Are harmful algal blooms (HABs) becoming the greatest inland water quality threat to public health and aquatic ecosystems? When HAB events require restrictions on fisheries, recreation, and drinking water uses of inland water bodies significant economic consequences result. Unfortunately, the magnitude, frequency, and duration of HABs in inland waters are poorly understood across spatiotemporal scales and differentially engaged among states, tribes, and territories. Harmful algal bloom impacts are not as predictable as those from conventional chemical contaminants, for which water quality assessment and management programs were primarily developed, because interactions among multiple natural and anthropogenic factors determine the likelihood and severity to which a HAB will occur in a specific water body. These forcing factors can also affect toxin production. Beyond site-specific water quality degradation caused directly by HABs, the presence of HAB toxins can negatively influence routine surface water quality monitoring, assessment, and management practices. Harmful algal blooms present significant challenges for achieving water quality protection and restoration goals when these toxins confound interpretation of monitoring results and environmental quality standards implementation efforts for other chemicals and stressors. Whether HABs presently represent the greatest threat to inland water quality is debatable, though in inland waters of developed countries they typically cause more severe acute impacts to environmental quality than conventional chemical contamination events. The authors identify several timely research needs. Environmental toxicology, environmental chemistry, and risk-assessment expertise must interface with ecologists, engineers, and public health practitioners to engage the complexities of HAB assessment and management, to address the forcing factors for HAB formation, and

  11. Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

    Directory of Open Access Journals (Sweden)

    M. Fader

    2015-06-01

    Full Text Available Climate and land use change in the Mediterranean region is expected to affect natural and agricultural ecosystems by decreases in precipitation, increases in temperature as well as biodiversity loss and anthropogenic degradation of natural resources. Demographic growth in the Eastern and Southern shores will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (LPJmL: nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development pave the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry, and opens the door for a large number of applications in the Mediterranean region, for example assessments on the consequences of land use transitions, the influence of management practices and climate change impacts.

  12. Bibliography of selected references on the effects of coal mine pollutants on aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, T F; Daniels, L K; Olsen, R D; Johnson, D O

    1979-12-01

    This bibliography contains more than 1400 references dealing with field and laboratory research on potential toxicities and disturbances known or postulated to be caused by pollutants found in coal mine effluents. The first of the three sections into which the bibliography is divided contains a select list of published bibliographies and literature reviews. In the second section are references on mine drainage studies, general references on environmental pollutants, and references dealing with two or more specific parameters. The third section includes references for 40 parameters under individual parameter headings. The multi parameter references in the second section are therefore also listed in the third section under individual headings. An author index is also provided.

  13. Effects of solar radiation on the abiotic and bacterially mediated carbon flux in aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Anesio, A.M.

    2000-05-01

    In this thesis, I studied some of the current aspects of organic matter photochemistry. I analyzed abiotic photo transformations of several types of dissolved (DOM) and particulate organic matter (POM). I also evaluated the effects of photo transformation of several types of DOM on bacteria. Finally, in a field experiment, I analyzed net effects of solar radiation on organic matter decomposition. DOM undergoes several transformations due to solar irradiation. One such transformation is photooxidation of organic matter into inorganic carbon. Results of this Thesis show that photooxidation is ubiquitous to all kinds of organic matter in both dissolved and particulate forms. The intensity of this process depends on several factors, including DOM composition, radiation type and time of exposure. Besides mineralization to inorganic carbon, DOM undergoes other chemical transformations due to UV radiation, with profound consequences to DOM availability for bacteria. Bioavailability was tested by measuring bacterial growth and respiration on irradiated and nonirradiated DOM from several types of humic matter and plant leachates. Irradiation of freshly-leached DOM often produced negative effects on bacteria, whereas irradiation of humic material was followed by stimulation of bacterial growth. The degree of stimulation seems to be related to the initial bioavailability of the DOM and to the capability of the DOM to produce hydrogen peroxide upon irradiation. Other factors also accounted for differences in bacterial response to photochemical modification of DOM, including length and type of irradiation exposure. The effects of solar radiation on litter decomposition were also evaluated using experiments that more closely mimic natural conditions. I could not observe differences between dry weight loss of leaves and culms exposed to solar radiation or kept in darkness, which may be explained by the fact that abiotic decomposition under solar radiation is counterbalanced by

  14. Modeling Microbial Biogeochemistry from Terrestrial to Aquatic Ecosystems Using Trait-Based Approaches

    Science.gov (United States)

    King, E.; Molins, S.; Karaoz, U.; Johnson, J. N.; Bouskill, N.; Hug, L. A.; Thomas, B. C.; Castelle, C. J.; Beller, H. R.; Banfield, J. F.; Steefel, C. I.; Brodie, E.

    2014-12-01

    Currently, there is uncertainty in how climate or land-use-induced changes in hydrology and vegetation will affect subsurface carbon flux, the spatial and temporal distribution of flow and transport, biogeochemical cycling, and microbial metabolic activity. Here we focus on the initial development of a Genome-Enabled Watershed Simulation Capability (GEWaSC), which provides a predictive framework for understanding how genomic information stored in a subsurface microbiome affects biogeochemical watershed functioning, how watershed-scale processes affect microbial function, and how these interactions co-evolve. This multiscale framework builds on a hierarchical approach to multiscale modeling, which considers coupling between defined microscale and macroscale components of a system (e.g., a catchment being defined as macroscale and biogeofacies as microscale). Here, we report our progress in the development of a trait-based modeling approach within a reactive transport framework that simulates coupled guilds of microbes. Guild selection is driven by traits extracted from, and physiological properties inferred from, large-scale assembly of metagenome data. Meta-genomic, -transcriptomic and -proteomic information are also used to complement our existing biogeochemical reaction networks and contributes key reactions where biogeochemical analyses are unequivocal. Our approach models the rate of nutrient uptake and the thermodynamics of coupled electron donors and acceptors for a range of microbial metabolisms including heterotrophs and chemolitho(auto)trophs. Metabolism of exogenous substrates fuels catabolic and anabolic processes, with the proportion of energy used for each based upon dynamic intracellular and environmental conditions. In addition to biomass development, anabolism includes the production of key enzymes, such as nitrogenase for nitrogen fixation or exo-enzymes for the hydrolysis of extracellular polymers. This internal resource partitioning represents a

  15. Impact of Forest Harvesting Operations on the Export of Total Mercury and Methylmercury to Aquatic Ecosystems

    Science.gov (United States)

    Sorensen, R.; Eklof, K.; Meili, M.; Akerblom, S.; Bishop, K.

    2009-12-01

    Forest harvesting operations have been reported to increase the levels of both total mercury (THg) and methylmercury (MeHg) in runoff water and downstream biota. In a series of full-scale experiments based on high-frequency monitoring of stream waters draining forested catchments in Sweden, we evaluated how runoff water chemistry was affected by forest harvesting as well as following site preparation for replantation and stump harvest. Stump harvesting is a forest management strategy that aims at increasing the supply of biofuels by recovering also the underground biomass when harvesting a stand. However, little is known about the local environmental impacts of stump harvest, within the catchment as well as downstream, as a result of changes in soil and surface water chemistry. Among other effects, concentrations or fluxes of THg and MeHg in soil and runoff waters may increase after such soil disturbances. The effects of forest harvesting and site preparation on runoff water chemistry were studied in three boreal catchments in northern Sweden using a paired-catchment approach (one of them an unharvested control). In the first two years after clearcutting, but before site preparation, there was no significant concentration response for either THg or MeHg relative to the control catchment, possibly due to very low soil disturbance. This raises the question of whether a major soil disturbance, such as that intentionally created by site preparation, is needed to generate the forestry effect on THg and MeHg reported in the literature, rather than just removal of trees alone. During the seven months following site preparation, MeHg and THg concentrations in the two site-prepared areas seemed to increase somewhat compared to the reference catchment. While not significant, the MeHg increase after site-preparation was 5-36% relative to the pre-harvest period and 4-8% relative to the harvest-only period. The updated assessment to be presented at the conference will include

  16. How forest management affects ecosystem services, including timber production and economic return

    DEFF Research Database (Denmark)

    Duncker, Philipp S.; Raulund-Rasmussen, Karsten; Gundersen, Per;

    2012-01-01

    Forest ecosystems deliver multiple goods and services and, traditionally, forest owners tend to have a high interest in goods in the form of merchantable wood. As a consequence, forest management often aims to increase timber production and economic returns through intervention into natural...

  17. Non-use Economic Values for Little-Known Aquatic Species at Risk: Comparing Choice Experiment Results from Surveys Focused on Species, Guilds, and Ecosystems

    Science.gov (United States)

    Rudd, Murray A.; Andres, Sheri; Kilfoil, Mary

    2016-09-01

    Accounting for non-market economic values of biological diversity is important to fully assess the benefits of environmental policies and regulations. This study used three choice experiments (species-, guild-, and ecosystem-based surveys) in parallel to quantify non-use values for little-known aquatic species at risk in southern Ontario. Mean willingness-to-pay (WTP) ranged from 9.45 to 21.41 per listing status increment under Canada's Species at Risk Act for both named and unnamed little-known species. Given the broad range of valuable ecosystem services likely to accrue to residents from substantial increases in water quality and the rehabilitation of coastal wetlands, the difference in WTP between species- and ecosystem-based surveys seemed implausibly small. It appeared that naming species—the `iconization' of species in two of the three surveys—had an important effect on WTP. The results suggest that reasonable annual household-level WTP values for little-known aquatic species may be 10 to 25 per species or 10 to 20 per listing status increment. The results highlighted the utility of using parallel surveys to triangulate on non-use economic values for little-known species at risk.

  18. Linking the evolution of habitat choice to ecosystem functioning: direct and indirect effects of pond-reproducing fire salamanders on aquatic-terrestrial subsidies.

    Science.gov (United States)

    Reinhardt, Timm; Steinfartz, Sebastian; Paetzold, Achim; Weitere, Markus

    2013-09-01

    Shifts in life history traits and in the behaviour of species can potentially alter ecosystem functioning. The reproduction of the central European fire salamander (Salamandra salamandra), which usually deposits its larvae in first-order streams, in small pool and pond-like habitats, is an example of a recent local adaptation in this species. Here we aimed to quantify the direct and indirect effects of the predatory larvae on the aquatic food webs in the ponds and on the flux of matter between the ponds and adjacent terrestrial habitats. Our estimates are based on biomass data of the present pond fauna as well as on the analysis of stomach content data, growth rates and population dynamics of the salamander larvae in pond habitats. By their deposition of larvae in early spring, female fire salamanders import between 0.07 and 2.86 g dry mass m(-2) larval biomass into the ponds. Due to high mortality rates in the larval phase and the relatively small size at metamorphosis of the pond-adapted salamanders compared to stream-adapted ones, the biomass export of the metamorphosed salamanders clearly falls below the initial biomass import. Catastrophic events such as high water temperatures and low oxygen levels may even occasionally result in mass mortalities of salamander larvae and thus in a net 100 % import of the salamander biomass into the pond food webs. Indirect effects further accelerate this net import of matter into the aquatic habitat, e.g. the feeding of salamanders on aquatic insect larvae with the emergence of terrestrial adults-thus preventing export-and on terrestrial organisms that fall on the water surface (supporting import). This study demonstrates that the adaptation of salamanders to pond reproduction can alter food web linkages across ecosystem boundaries by enhancing the flux of materials and energy from terrestrial (i.e. forest) to the aquatic (i.e. pond) habitat.

  19. Multiproxy evidence for terrestrial and aquatic ecosystem responses during the 8.2 ka cold event as recorded at Højby Sø, Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Rasmussen, Peter; Noe-Nygaard, Nanna;

    2010-01-01

    .2 ka cold event as registered in the Greenland ice cores. At Højby Sø, the climate anomaly appears to have started 200–250 yr earlier than the 8.2 ka cold event as the lake proxy data provide strong evidence for a precipitation-induced distinct increase in catchment soil erosion beginning around 8500...... cal yr BP. Alteration of the terrestrial environment then resulted in a major aquatic ecosystem change with nutrient enrichment of the lake and enhanced productivity, which lasted until c. 7900 cal yr BP. Keywords: 8.2 ka cold event; Lake sediments; Palaeoclimate; Pollen; Macrofossils; Geochemistry...

  20. Environmental risk assessment of three selective serotonin reuptake inhibitors in the aquatic environment: a case study including a cocktail scenario.

    Science.gov (United States)

    Styrishave, Bjarne; Halling-Sørensen, Bent; Ingerslev, Flemming

    2011-01-01

    We present an environmental risk assessment of three selective serotonin reuptake inhibitors (SSRIs; citalopram, sertraline, and fluoxetine) in the aquatic environment based on two case scenarios. Abiotic and biotic degradation experiments and sorption estimates were used to predict environmental concentrations of three SSRIs from the wastewater of two psychiatric hospitals, the primary sector, and wastewater entering and leaving wastewater treatment plants (WWTPs). Assuming a sewage treatment retention time of 8 h, abiotic degradation was low, for all three SSRIs inhibitors, ranging between 0 and 2% for hydrolysis and 0 and 6% for photolysis. The biodegradation was also slow, ranging from 0 to 3% within an 8-h period. In untreated sewage, citalopram (CIT) and sertraline (SER) concentrations may be high enough to exert effects on the aquatic biota (CIT: 0.19-10.3 µg/L; SER: 0.14-17.1 µg/L). Removal of the pharmaceuticals is due primarily to sorption in the WWTP. Sertraline was estimated to have the highest concentrations in the sewage effluents, 4.4 and 19.9 ng/L for the two cases, respectively. In treated wastewater, individual SSRI concentrations are probably too low to exert effects on biota. By using concentration addition, a cocktail exposure scenario was estimated. The predicted concentration in the biota calculated from the cocktail effect was 0.05 and 0.16 nmol/g for the two cases, respectively, and SER was found to give the highest contribution to this cocktail effect. The results indicate that the concentrations in the wastewater effluents are one to two orders of magnitude lower than the concentrations likely to cause an effect in the aquatic biota.

  1. Science for Managing Riverine Ecosystems: Actions for the USGS Identified in the Workshop "Analysis of Flow and Habitat for Instream Aquatic Communities"

    Science.gov (United States)

    Bencala, Kenneth E.; Hamilton, David B.; Petersen, James H.

    2006-01-01

    Federal and state agencies need improved scientific analysis to support riverine ecosystem management. The ability of the USGS to integrate geologic, hydrologic, chemical, geographic, and biological data into new tools and models provides unparalleled opportunities to translate the best riverine science into useful approaches and usable information to address issues faced by river managers. In addition to this capability to provide integrated science, the USGS has a long history of providing long-term and nationwide information about natural resources. The USGS is now in a position to advance its ability to provide the scientific support for the management of riverine ecosystems. To address this need, the USGS held a listening session in Fort Collins, Colorado in April 2006. Goals of the workshop were to: 1) learn about the key resource issues facing DOI, other Federal, and state resource management agencies; 2) discuss new approaches and information needs for addressing these issues; and 3) outline a strategy for the USGS role in supporting riverine ecosystem management. Workshop discussions focused on key components of a USGS strategy: Communications, Synthesis, and Research. The workshop identified 3 priority actions the USGS can initiate now to advance its capabilities to support integrated science for resource managers in partner government agencies and non-governmental organizations: 1) Synthesize the existing science of riverine ecosystem processes to produce broadly applicable conceptual models, 2) Enhance selected ongoing instream flow projects with complementary interdisciplinary studies, and 3) Design a long-term, watershed-scale research program that will substantively reinvent riverine ecosystem science. In addition, topical discussion groups on hydrology, geomorphology, aquatic habitat and populations, and socio-economic analysis and negotiation identified eleven important complementary actions required to advance the state of the science and to

  2. Environmental behaviour of short-chain chlorinated paraffins in aquatic and terrestrial ecosystems of Ny-Ålesund and London Island, Svalbard, in the Arctic.

    Science.gov (United States)

    Li, Huijuan; Fu, Jianjie; Pan, Wenxiao; Wang, Pu; Li, Yingming; Zhang, Qinghua; Wang, Yawei; Zhang, Aiqian; Liang, Yong; Jiang, Guibin

    2017-07-15

    The environmental behaviour of short-chain chlorinated paraffins (SCCPs) was investigated in both aquatic and terrestrial ecosystems in the Arctic. The mean concentrations of SCCPs in the aquatic and terrestrial samples were 178.9ng/g dry weight (dw) and 157.2ng/g dw, respectively. Short carbon chain (C10) and less-chlorinated (Cl6) congener groups were predominant in the Arctic samples, accounting for 48.6% and 34.8% of the total SCCPs, respectively. The enrichment of lighter SCCP congener groups (i.e., fewer chlorine atoms with shorter carbon chain lengths) indicated that the fractionation process occurred during long-range transport. The biomagnification factor (BMF) was 0.46 from gammarid to cod, which indicated that the SCCPs did not biomagnify between these two species. The soil-vegetation bioaccumulation factor (BAF) of SCCPs was 29.9, and C13 and Cl7, 8 congener groups tended to accumulate in the terrestrial vegetation. Regression analysis (BAFs=10.9×#C+5.6×#Cl-125.2, R=0.53, P<0.01) showed that the number of carbon and chlorine atoms influenced the bioaccumulative behaviour of SCCPs and suggested that the number of carbon atoms had a greater influence on the BAFs of SCCPs in the terrestrial ecosystem than did the number of chlorine atoms.

  3. Modelling Pb, Zn and As transfer from terrestrial to aquatic ecosystems during the ice-free season in three Pyrenean catchments.

    Science.gov (United States)

    Bacardit, Montserrat; Camarero, Lluís

    2010-11-01

    Long-range atmospheric trace element contamination affecting natural systems has occurred since early historical times in the Northern Hemisphere. In relatively remote sites, soils are the largest reservoir of these airborne contaminants. Trace elements stored in soils can later be remobilized and thus soils are a potential delayed, long-lasting source of contamination for the aquatic ecosystems. Here we measured the atmospheric deposition and in-lake fluxes in order to model the transfer of Pb, Zn and As from terrestrial to aquatic ecosystems during the snow- and ice-free season in three mountain catchments in the Central Pyrenees. According to the model, there was a net export of Pb and As from the catchments. We postulate that accumulated anthropogenic Pb contamination and the weathering of As-rich rocks are the most likely sources. In contrast, Zn was largely retained in the catchment. For Pb and As, the terrestrial inputs were >91% and for Zn were ~71% of the total inputs to the lakes. Nearly all Pb entering the lakes was retained in the sediments whereas 5-38% of As and Zn was lost through the outflow. We were unable to adjust the model for Zn for one of the lakes. The uptake by macrophytes could be a considerable sink for Zn, which was not considered in our transport model.

  4. Effects of the global changes on the aquatic ecosystems in West Europe - role of the plankton communities; Effets des changements globaux sur les ecosystemes aquatiques d'Europe Occidentale - role des communautes planctoniques

    Energy Technology Data Exchange (ETDEWEB)

    Souissi, S. [Universite des Sciences et Technologies de Lille, Ecosystem COmplexity REsearch Group, Station Marine de Wimereux, CNRS - FRE 2816 ELICO, 62 - Wimereux (France)

    2007-07-01

    Examination of long-term records of aquatic ecosystems has provided useful information to find out their major driving forces. Understanding the impact of climate change on these ecosystems, the management of their resources and the extrapolation between sites are the main scopes of actual and emerging studies. Such goals can be achieved by inter-site and inter-ecosystem comparisons. This approach was undertaken during our project which has the originality to tackle with marine and freshwater ecosystems. It allowed us to compile and validate several multi-decadal time series of planktonic and other physical driving forces at local and regional scales. Then, the same methodology based on the analysis of the variability of climate indices and biological data across several spatial scales was used. The different ecosystems analyzed here showed clear response to the North Atlantic climate variability. Although the local differences abrupt changes in community composition occurred in all ecosystems in the middle of the years 80. During this period there was also a major shift in climatic conditions during winter and early spring, suggesting an impact of climatic factors. Phenological changes were also observed in plankton communities in all sites. The consequences of the modifications of plankton dynamics on higher trophic levels were also showed. Fluctuations in plankton have resulted in long-term changes in cod recruitment in the North Sea (bottom-up control). On the other hand, both climate change and the improvement of trophic status in Geneva Lake favored the outbreak of whitefish during the years 90. Lower larval mortality and better recruitment are supposed to be linked to faster growth associated with warmer temperatures and better food conditions induced by better temporal overlap between larvae hatching and zooplankton development. (author)

  5. Optimization of Aquatic-Terrestrial Ecosystem in Relation to Soil Nitrogen Status for the Cultivation of Fish and Aquatic Food Crops of the Indian Subtropics

    Directory of Open Access Journals (Sweden)

    A.M. Puste

    2001-01-01

    Full Text Available A case study was undertaken during wet and postwet seasons to improve the perennial and alternate submerged saucer-shaped ponded lands (tal and semi-tal lands in the coasts and northeastern plains of the Indian subtropics through pisciculture and cultivation of starch- and protein-rich aquatic food crops like water chestnut (Trapa bispinosa Roxb. and makhana or fox nut (Euryale ferox Salisb.. The study revealed that the physico-chemical properties of soils (pH, organic C, organic matter, available N, P, and K as well as quality of water (pH, EC, BOD, COD, CO3+, HCO3�, NO3-N, SO4-S, and Cl�, growing fish, makhana, and water chestnut was remarkably influenced by different moisture regimes and exhibited a significant improvement of soil health. The amount of organic C, available N, P, and K content were found significantly highest in the treatment where makhana was grown under alternate flooding and drying situation with a depth >2 m as compared to other treatments. Such enrichment of soil fertility, particularly in available N and P content, might be due to the accumulation of considerable amounts of biomass and fish excreta and their subsequent decomposition in situ in the soils. Therefore, the present study suggests that the N-enriched soil may effectively be utilized further for growing subsequent arable crops surroundings during summer season, which not only saves the amount of applied N fertilizer but also increases the apparent N efficiency with simultaneous increase in yield, and would benefit the farmers in this region.

  6. Microbial community analysis in the roots of aquatic plants and isolation of novel microbes including an organism of the candidate phylum OP10.

    Science.gov (United States)

    Tanaka, Yasuhiro; Tamaki, Hideyuki; Matsuzawa, Hiroaki; Nigaya, Masahiro; Mori, Kazuhiro; Kamagata, Yoichi

    2012-01-01

    A number of molecular ecological studies have revealed complex and unique microbial communities in various terrestrial plant roots; however, little is known about the microbial communities of aquatic plant roots in spite of their potential use for water quality improvement in aquatic environments (e.g. floating treatment wetland system). Here, we report the microbial communities inhabiting the roots of emerged plants, reed (Phragmites australis) and Japanese loosestrife (Lythrum anceps), collected from a floating treatment wetland in a pond by both culture-independent and culture-dependent approaches. Culture-independent analysis based on 16S rRNA gene sequences revealed that the microbial compositions between the two aquatic plant roots were clearly different (e.g. the predominant microbe was Betaproteobacteria for reed and Alphaproteobacteria for Japanese loosestrife). In comparisons of microbial communities between the plant roots and pond water taken from near the plants, the microbial diversity in the plant roots (e.g. 4.40-4.26 Shannon-Weiner index) were higher than that of pond water (e.g. 3.15 Shannon-Weiner index). Furthermore, the plant roots harbored 2.5-3.5 times more phylogenetically novel clone phylotypes than pond water. The culture-dependent approach also revealed differences in the microbial composition and diversity among the two plant roots and pond water. More importantly, compared to pond water, we succeeded in isolating approximately two times more novel isolate phylotypes, including a bacterium of candidate phylum OP10 (recently named Armatimonadetes) from the plant roots. These findings suggest that aquatic plants roots are significant sources for a variety of novel organisms.

  7. The adaptational strategies of the hindlimb muscles in the Tenrecidae species including the aquatic web-footed tenrec (Limnogale mergulus).

    Science.gov (United States)

    Endo, Hideki; Yonezawa, Takahiro; Rakotondraparany, Felix; Sasaki, Motoki; Hasegawa, Masami

    2006-07-01

    The hindlimb muscles in four species of Tenrecidae (Oryzoryctinae: Talazac long-tailed tenrec and web-footed tenrec, Tenrecinae: lesser hedgehog tenrec, and streaked tenrec), were examined macroscopically. The weight ratios of the muscles to the body in the oryzoryctinid species are larger than those in Tenrecinae, since the Oryzoryctinae species have an obviously smaller body from the evolutionary point of view. It can be primarily pointed out that the adaptation of the body size is different between the two subfamilies, and secondarily, that functional adaptation to locomotion is complete within each subfamily. The weight data and the morphological findings demonstrate that the web-footed tenrec possesses an extraordinary large M. semimembranosus in comparison to the Talazac long-tailed tenrec in their weight ratios. This muscle may act as a strong flexor motor in the knee joint during the aquatic locomotion of the web-footed tenrec. Since the other muscles of the web-footed tenrec are similar to those of the Talazac long-tailed tenrec regards weight ratio data, we think that the web-footed tenrec may have derived from a terrestrial ancestor such as the long-tailed tenrecs. In Tenrecinae the streaked tenrec is equipped with larger Mm. adductores, M. semimembranosus and M. triceps surae than the lesser hedgehog tenrec. This species is adapted to fossorial life derived from non-specialized ancestors within the evolutionary lines of the spiny tenrecs.

  8. Modeling of hydroecological feedbacks predicts distinct classes of landscape pattern, process, and restoration potential in shallow aquatic ecosystems

    Science.gov (United States)

    Larsen, Laurel G.; Harvey, Judson W.

    2011-03-01

    It is widely recognized that interactions between vegetation and flow cause the emergence of channel patterns that are distinct from the standard Schumm classification of river channels. Although landscape pattern is known to be linked to ecosystem services such as habitat provision, pollutant removal, and sustaining biodiversity, the mechanisms responsible for the development and stability of different landscape patterns in shallow, vegetated flows have remained poorly understood. Fortunately, recent advances have made possible large-scale models of flow through vegetated environments that can be run over a range of environmental variables and over timescales of millennia. We describe a new, quasi-3D cellular automata model that couples simulations of shallow-water flow, bed shear stresses, sediment transport, and vegetation dynamics in an efficient manner. That efficiency allowed us to apply the model widely in order to determine how different hydroecological feedbacks control landscape pattern and process in various types of wetlands and floodplains. Distinct classes of landscape pattern were uniquely associated with specific types of allogenic and autogenic drivers in wetland flows. Regular, anisotropically patterned wetlands were dominated by allogenic processes (i.e., processes driven by periodic high water levels and flow velocities that redistribute sediment), relative to autogenic processes (e.g., vegetation production, peat accretion, and gravitational erosion). These anistropically patterned wetlands are therefore particularly prone to hydrologic disturbance. Other classes of wetlands that emerged from simulated interactions included maze-patterned, amorphous, and topographically noisy marshes, open marsh with islands, banded string-pool sequences perpendicular to flow, parallel deep and narrow channels flanked by marsh, and ridge-and-slough patterned marsh oriented parallel to flow. Because vegetation both affects and responds to the balance between the

  9. Ecosystem services in the St. Louis River AOC

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dataset indicates the presence or absence of each ecosystems service at each coordinate Location. Also included are depth, fetch, and aquatic vegetation data. See...

  10. Heat Transfer Processes for the Thermal Energy Balance of Organisms. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Stevenson, R. D.

    This module is part of a series designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module describes heat transfer processes involved in the exchange of heat…

  11. Bioavailability of Polycyclic Aromatic Hydrocarbons in aquatic ecosystems : influence of natural and anthropic organic matter; Biodisponibilite des hydrocarbures aromatiques polycycliques dans les ecosystemes aquatiques: influence de la matiere organique naturelle et anthropique

    Energy Technology Data Exchange (ETDEWEB)

    Gourlay, C.

    2004-11-01

    Aquatic ecosystems receive micro-pollutants. They also contain organic matter (OM) of natural and anthropogenic origins. The contaminant bioavailability in aquatic media is determined by the interactions between contaminants and OM. This work deals with the influence of organic matter from anthropogenic media on the bioavailability of hydrophobic organic pollutants. Polycyclic Aromatic Hydrocarbons (PAHs) have been used as model contaminants, since they are widely spread in urban media. In anthropogenic media, some OM may be bio-degraded. Up to now, most researches focused on the interactions between contaminants and humic OM that are mostly non-degradable, using physico-chemical characterizations of OM. On the contrary, in this work, the biodegradability of OM was deliberately taken into account. Indeed, we assume that the contaminant affinity for OM evolves during OM biodegradation, so that pollutants may be released in a bio-available form and then may be bond again by biodegradation sub-products. In laboratory evaluation, PAH bioavailability was assessed through the measurements of the bioaccumulation in Daphnia magna. The influence of organic matter on the bioavailability of PAHs and the evolution of this influence along OM bacterial mineralization were proved, as well as the strong binding efficiency of degradation by-products. A model of observed phenomena was elaborated. These observations about urban and natural OM effect were compared to in situ PAH bioavailability measurements in the river Seine basin. In this case, the bioavailability was estimated using Semi-Permeable Membrane Device (SPMD) sampling technique. (author)

  12. Wetland Biomass Production: emergent aquatic management options and evaluations. A final subcontract report. [Includes a bibliography containing 686 references on Typha from biological abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, D.C.; Dubbe, D.R.; Garver, E.G.; Linton, P.J.

    1984-07-01

    The high yield potential and attractive chemical composition of Typha make it a particularly viable energy crop. The Minnesota research effort has demonstrated that total annual biomass yields equivalent to 30 dry tonnes/ha (13 tons/acre) are possible in planted stands. This compares with yields of total plant material between 9 and 16 dry tonnes/ha (4 to 7 tons/acre) in a typical Minnesota corn field. At least 50% of the Typha plant is comprised of a belowground rhizome system containing 40% starch and sugar. This high level of easily fermentable carbohydrate makes rhizomes an attractive feedstock for alcohol production. The aboveground portion of the plant is largely cellulose, and although it is not easily fermentable, it can be gasified or burned. This report is organized in a manner that focuses on the evaluation of the management options task. Results from stand management research performed at the University of Minnesota during 1982 and 1983 are integrated with findings from an extensive survey of relevant emergent aquatic plant research and utilization. These results and findings are then arranged in sections dealing with key steps and issues that need to be dealt with in the development of a managed emergent aquatic bio-energy system. A brief section evaluating the current status of rhizome harvesting is also included along with an indexed bibliography of the biology, ecology, and utilization of Typha which was completed with support from this SERI subcontract. 686 references, 11 figures, 17 tables.

  13. Benthic indicators to use in Ecological Quality classification of Mediterranean soft bottom marine ecosystems, including a new Biotic Index

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2012-12-01

    Full Text Available A general scheme for approaching the objective of Ecological Quality Status (EcoQ classification of zoobenthic marine ecosystems is presented. A system based on soft bottom benthic indicator species and related habitat types is suggested to be used for testing the typological definition of a given water body in the Mediterranean. Benthic indices including the Shannon-Wiener diversity index and the species richness are re-evaluated for use in classification. Ranges of values and of ecological quality categories are given for the diversity and species richness in different habitat types. A new biotic index (BENTIX is proposed based on the relative percentages of three ecological groups of species grouped according to their sensitivity or tolerance to disturbance factors and weighted proportionately to obtain a formula rendering a five step numerical scale of ecological quality classification. Its advantage against former biotic indices lies in the fact that it reduces the number of the ecological groups involved which makes it simpler and easier in its use. The Bentix index proposed is tested and validated with data from Greek and western Mediterranean ecosystems and examples are presented. Indicator species associated with specific habitat types and pollution indicator species, scored according to their degree of tolerance to pollution, are listed in a table. The Bentix index is compared and evaluated against the indices of diversity and species richness for use in classification. The advantages of the BENTIX index as a classification tool for ECoQ include independence from habitat type, sample size and taxonomic effort, high discriminative power and simplicity in its use which make it a robust, simple and effective tool for application in the Mediterranean Sea.

  14. Radionuclide transport and uptake in coastal aquatic ecosystems: a comparison of a 3D dynamic model and a compartment model.

    Science.gov (United States)

    Erichsen, Anders Christian; Konovalenko, Lena; Møhlenberg, Flemming; Closter, Rikke Margrethe; Bradshaw, Clare; Aquilonius, Karin; Kautsky, Ulrik

    2013-05-01

    In safety assessments of underground radioactive waste repositories, understanding radionuclide fate in ecosystems is necessary to determine the impacts of potential releases. Here, the reliability of two mechanistic models (the compartmental K-model and the 3D dynamic D-model) in describing the fate of radionuclides released into a Baltic Sea bay is tested. Both are based on ecosystem models that simulate the cycling of organic matter (carbon). Radionuclide transfer is linked to adsorption and flows of carbon in food chains. Accumulation of Th-230, Cs-135, and Ni-59 in biological compartments was comparable between the models and site measurements despite differences in temporal resolution, biological state variables, and partition coefficients. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate means. The D-model enables estimates at high spatio-temporal resolution. The K-model, being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take advantage of their respective strengths.

  15. Radionuclide transport and uptake in coastal aquatic ecosystems - a comparison of a 3D dynamic model and a compartment model

    Energy Technology Data Exchange (ETDEWEB)

    Konovalenko, L.; Bradshaw, C. [The Department of Ecology, Environment and Plant Sciences Stockholm University (Sweden); Erichsen, A.C.; Moehlenberg, F. [Ecological and Environmental Department DHI (Sweden); Kautsky, U. [Swedish Nuclear Fuel and Waste Management Co - SKB (Sweden)

    2014-07-01

    In safety assessments of underground radioactive waste repositories, understanding the fate of radionuclides in ecosystems is necessary. Here, two mechanistic models (K- and D- model) describing the fate of radionuclides released into a Baltic Sea bay were compared. Both are based on ecosystem models that simulate the cycling of organic matter. Parallel to adsorption, transfer of radionuclides is linked to flows of organic matter (carbon) in food chains. Despite differences in temporal resolution, biological state variables and partition coefficients, the accumulation of Th-230, Cs-135 and Ni-59 in biological compartments was comparable between the models and with site measurements. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate mean values. The D-model enables estimates at high spatio-temporal resolution. The K-model being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take full advantage of their respective strengths. Document available in abstract form only. (authors)

  16. Radionuclide Transport and Uptake in Coastal Aquatic Ecosystems: A Comparison of a 3D Dynamic Model and a Compartment Model

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe [Ecological and Environmental Dept., DHI, Hoersholm (Denmark)], E-mail: aer@dhigroup.com; Konovalenko, Lena; Bradshaw, Clare [The Dept. of Ecology, Environment and Plant Sciences, Stockholm Univ., Stockholm (Sweden); Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co. (SKB), Stockholm (Sweden); Aquilonius, Karin [Studsvik Nuclear AB, Nykoeping (Sweden)

    2013-05-15

    In safety assessments of underground radioactive waste repositories, understanding radionuclide fate in ecosystems is necessary to determine the impacts of potential releases. Here, the reliability of two mechanistic models (the compartmental K-model and the 3D dynamic D-model) in describing the fate of radionuclides released into a Baltic Sea bay is tested. Both are based on ecosystem models that simulate the cycling of organic matter (carbon). Radionuclide transfer is linked to adsorption and flows of carbon in food chains. Accumulation of Th-230, Cs-135, and Ni-59 in biological compartments was comparable between the models and site measurements despite differences in temporal resolution, biological state variables, and partition coefficients. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate means. The D-model enables estimates at high spatio-temporal resolution. The K-model, being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take advantage of their respective strengths.

  17. Service Function Analysis and Value Evaluation of Aquatic Ecosystem in Yinchuan%银川市水生态系统服务功能价值评价

    Institute of Scientific and Technical Information of China (English)

    杨美玲; 马鹏燕

    2011-01-01

    地处西北干旱半干旱区的银川市,有限的水资源能否支撑经济社会可持续发展,已成为亟需解决的问题.为了对银川市水生态系统的服务价值进行有效评估,笔者以相关统计文献为基础,从水资源的生态、生产和生活功能出发,采用影子价格法、替代成本法、旅行费用法、恢复费用法等方法,对银川市水生态系统服务价值进行了评价.结果表明:(1)自2003年到2008年,由于城市工业用水、生活用水量的逐年增大,城市淡水供应价值逐年上升.今后,随着银川市工业化、城市化的发展,其人口规模和经济规模都必将急剧扩大,城市用水中的工业用水和生活用水将继续加速上升.(2)城市淡水供应价值和休闲娱乐价值占GDP的比重均呈逐年下降的趋势.表明银川市水生态系统的服务价值严重滞后于经济的发展,在城市GDP增长中的贡献越来越小.%The city of Yinchuan that located in the northwest of arid and semiarid zones, whether limited water resources can support sustainable economic and social development has become urgent problem. In order to have an effective assessment about the value of aquatic ecosystem, based on the relevant statistical literature, and using shadow price method, replacement cost method, travel cost method and recovery fees and other methods, the author evaluated the value of aquatic ecosystem service of Yinchuan. The results showed that: (1) from 2003 to 2008, as urban industrial water, living water consumption increased every year, the value of urban water supply increased year by year. In the future, with the development of industrialization and urbanization, the population scale and economic scale would expand rapidly, the amount of industrial water and domestic water would continue to be accelerated. (2) The proportion of urban water supply and recreational value of the GDP appeared a declining trend. This showed that the value of aquatic ecosystem

  18. Research on Interrelationship between some Species of Freshwater Fish and Helmintic Larvae within Aquatic Ecosystems Polluted with Heavy Metals

    Directory of Open Access Journals (Sweden)

    Laura Daniela Urdeş

    2010-10-01

    Full Text Available The objective of this study was to investigate the ability of some larvae of cestodes and nematodes which live infreshwater fish (intermediate hosts, to exhibit an uptake of heavy metals.According to some scientifical papers treating this subject, only adult worms were able to absorb successfully heavymetals within their hosts. Furthermore, it is believed that only the adults would act as biofilters and consequently astrustworthy indicators of environmental pollution.This study, carried out on the Danube Delta area, comes to prove the ability of the larvae to absorb heavy metalswithin their hosts, even when the pollution level with respect to heavy metals is very low.Following the biochemical analyses of water, sediment, aquatic plants, larvae and fish tissues (liver and musclesamples, it resulted that the larvae were able to absorb important quantities within their hosts, so that only scarceamounts to be found in the muscle and liver. Both parasites were able to accumulate some heavy metals within theirhosts, although only one of them did it successfully.

  19. Effects of metal pollution on sediments in a highly saline aquatic ecosystem: case of the Moknine continental Sebkha (eastern Tunisia).

    Science.gov (United States)

    Wali, Ahmed; Kawachi, Atsushi; Bougi, Mohamed Seddik Mahmoud; Dhia, Hamed Ben; Isoda, Hiroko; Tsujimura, Maki; Ksibi, Mohamed

    2015-04-01

    Potential contamination of the sediments in the Sebkha of Moknine (Tunisia) ecosystem was assessed by means of enrichment factors (EFs) estimated against reference sediment located ≈70 km away from the Sebkha. The use of EFs is recommended as a reliable method for heavy metal contamination assessment, provided that (1) element contents are corrected following a careful normalization procedure, and (2) the reference sediment is unaffected by anthropogenic alterations. The degree of contamination was assessed by the modified contamination degree approach. The obtained results indicated that surface sediments were enriched up to 22.9, 13.2, 5.46 and 3.19 times with Pb, Cu, Cr and Zn, respectively. Lower enrichment factors for Ni and Co suggested that anthropogenic sources were less important for these metals. The modified degree of contamination showed that the sediments in the Sebkha of Moknine have suffered significant systematic heavy metal contamination following catchment urbanization and industrialization .

  20. The ``C.E.B.A.S. MINI-MODULE'': A self-sustaining closed aquatic ecosystem for spaceflight experimentation

    Science.gov (United States)

    Blüm, V.; Andriske, M.; Ludwig, Ch.; Paaßen, U.; Voeste, D.

    The C.E.B.A.S. MINI-MODULE is the miniaturized space flight version of the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.). It fits into a large middeck locker tray and is scheduled to be flown in the STS 85 and in the NEUROLAB missions. Its volume is about 9 liters and it consists of two animal tanks, a plant cultivator, and a bacteria filter in a monolithic design. An external sensor unit is connected to a data acquisition/control unit. The system integrates its own biological life support. The CO2 exhaled by the consumers (fishes, snails, microorganisms) is assimilated by water plants (Ceratophyllum demersum) which provide them with oxygen. The products of biomass degradation and excretion (mainly ammonia ions) are converted by bacteria into nitrite and nitrate. The latter is taken up by the plants as a nitrogen source together with other ions like phosphate. The plants convert light energy into chemical energy and their illumination is regulated via the oxygen concentration in the water by the control unit. In ground laboratory tests the system exhibited biological stability up to three month. The buffer capacity of the biological filter system is high enough to eliminate the degradation products of about one half of the dead animal biomass as shown in a ``crash test''. A test series using the laboratory model of the flight hardware demonstrated the biological stability and technical reliability with mission-identical loading and test duration. A comprehensive biological research program is established for the C.E.B.A.S. MINI-MODULE in which five German and three U.S.-American universities as well as the Russian Academy of Sciences are involved.

  1. Results 2005 of the surveillance of the artificial radioactivity levels of aquatic ecosystems in the basin of Seine-Normandy. Riviere 2005; Resultats 2005 de la surveillance des niveaux de la radioactivite artificielle d'ecosystemes aquatiques appartenant au bassin Seine-Normandie. Riviere 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Set up in 2004 by the A.C.R.O. the citizens network of radioecological surveillance, information and evaluation (R.I.V.I.E.R.E.) aims at making a follow-up of the radioactive contamination of the aquatic ecosystems on the scale of the Seine-Normandy pond: from Nogent-on-Seine to La Hague and from the Mont-Saint-Michel to the Treport. The peculiarity of this network, which also makes its strength is to associate strictly all those who wish to appropriate the knowledge of the radioactivity levels around to them. With R.I.V.I.E.R.E., the citizen is at the same moment an author and an actor of the surveillance of his environment as his information. An approach defended by the A.C.R.O. since about 20 years and which has no equivalent anywhere else. This project has four main objectives: to know the levels and the tendencies of the present radioactivity in the main aquatic ecosystems of the Seine-Normandy widened pond, and so feed a data base including more than 3000 analysis (limited to the gamma radioactivity and to the tritium); to allow the citizens who put a lot to appropriate the knowledge and the indispensable references to understand the radioactivity of their environment; to establish a support in the public information about the radioactivity in environment; to supply data to the national network of measures of the radioactivity in environment, network established by decree recently and in charge of the evaluation of the public exposure. (N.C.)

  2. Report on stakeholder evaluation of highland aquatic resources

    DEFF Research Database (Denmark)

    Lund, Søren

    This report gives an overview of completed research activities on the value ascribed by users, local communities and stakeholders to functions, goods and services (including non‐use values) derived from the aquatic resources in the study areas. The perceived impact of factors such as environmenta...... to better characterise constraints and conflicts, and build consensus concerning opportunities for better conservation and management of highland aquatic resources, opportunities for livelihoods enhancement and sustaining ecosystem services....

  3. Proceedings of the Workshop on Aquatic Ecosystem Modeling and Assessment Techniques for Application within the U.S. Army Corps of Engineers.

    Science.gov (United States)

    1998-04-01

    relationships such as the Holling type II function (which include a maximum rate at which predators can consume prey); ratio-dependent models ( Arditi and...USACE Workshop on Ecosystem Modeling & Assessment Akcakaya, H.R., Arditi , R., and Ginzburg, L.R. 1995. Ratio-dependent predation: an abstraction that...works. Ecology 76:995-1004. Arditi , R., and Ginzburg, L.R. 1989. Coupling in predator-prey dynamics: ratio-dependence. Journal of Theoretical Biology

  4. Using High-Resolution Models to Predict the Effects of Climate Change on Aquatic Ecosystems in the Crown of the Continent

    Science.gov (United States)

    Jones, L.; Muhlfeld, C.; Marshall, L. A.

    2013-12-01

    Climate trends and projections have prompted interest in assessing the thermal sensitivity of aquatic species. How species will adapt and respond to these changes is uncertain, however, climatic and hydrologic changes may shift species habitat distributions and physiological functions both spatially and temporally. This is particularly true for salmonids (e.g., trout, char, and salmon), which are cold-water species strongly influenced by changes in temperature, flow, and physical habitat conditions. Therefore, understanding how habitats are likely to change and how species may respond to changes in climatic conditions is critical for developing conservation and management strategies. The purpose of this study is to develop a high-resolution stream temperature model for the Crown of the Continent Ecosystem (CCE) to simulate potential climate change impacts on thermal regimes throughout the riverscape. A spatially explicit statistical regression model is coupled with high-resolution climate data such as air temperature, precipitation, solar radiation, baseflow and surface runoff. This empirically based model is used to predict daily stream temperatures under historic, current and forecasted climate conditions. The model is parameterized with empirical stream temperature data, which has been gathered from agencies across the region. The current database of empirical stream temperature data consists of over 800 sites throughout the CCE, which provide time series data to the model application. The biological integration and application of this model is on bull trout (Salvelinus confluentus) populations within the CCE. The model will be used to assess species vulnerabilities caused by spatial and temporal changes in stream temperature and hydrology. By evaluating the magnitude, timing and duration of climatic changes on the riverscape, we can more accurately assess potential vulnerabilities of critical life history traits, such as growth potential, spawning migrations

  5. Microbial ecology of Antarctic aquatic systems.

    Science.gov (United States)

    Cavicchioli, Ricardo

    2015-11-01

    The Earth's biosphere is dominated by cold environments, and the cold biosphere is dominated by microorganisms. Microorganisms in cold Southern Ocean waters are recognized for having crucial roles in global biogeochemical cycles, including carbon sequestration, whereas microorganisms in other Antarctic aquatic biomes are not as well understood. In this Review, I consider what has been learned about Antarctic aquatic microbial ecology from 'omic' studies. I assess the factors that shape the biogeography of Antarctic microorganisms, reflect on some of the unusual biogeochemical cycles that they are associated with and discuss the important roles that viruses have in controlling ecosystem function.

  6. Toxicity assessment of boron (B) by Lemna minor L. and Lemna gibba L. and their possible use as model plants for ecological risk assessment of aquatic ecosystems with boron pollution.

    Science.gov (United States)

    Gür, Nurcan; Türker, Onur Can; Böcük, Harun

    2016-08-01

    As many of the metalloid-based pollutants, the boron (B) toxicity issues have aroused more and more global attentions, especially concerning drinking water sources which flow through boron-rich areas. Therefore, feasible and innovative approaches are required in order to assess B toxicity in aquatic ecosystems. In this study, the toxic effects of B on Lemna minor L. and Lemna gibba L. were investigated using various endpoints including number of fronds, growth rates, dry biomass and antioxidants enzymatic activities. Lemna species were exposed to B concentrations of 2 (control), 4, 8, 16, 32, 64 and 128 mg L(-1) for a test period of 7 days. The results demonstrated that plant growth was significantly reduced when the B concentration reached 16 mg L(-1). Furthermore, our results also concluded that among the antioxidative enzymes, SOD, APX and GPX can serve as important biomarkers for B-rich environment. The present results suggested that L. minor and L. gibba are very useful model plants for phytoremediation of low-B contaminated wastewater and they are also suitable options for B biomonitoring due to high phototoxic sensitivity against B. In this respect, the scientific insight of the present study is to fill the gaps in the research about the use of L. minor and L. gibba in ecotoxicological research associated with B toxicity.

  7. Constructed wetlands to reduce metal pollution from industrial catchments in aquatic Mediterranean ecosystems: a review to overcome obstacles and suggest potential solutions.

    Science.gov (United States)

    Guittonny-Philippe, Anna; Masotti, Véronique; Höhener, Patrick; Boudenne, Jean-Luc; Viglione, Julien; Laffont-Schwob, Isabelle

    2014-03-01

    In the Mediterranean area, surface waters often have low discharge or renewal rates, hence metal contamination from industrialised catchments can have a high negative impact on the physico-chemical and biological water quality. In a context of climate and anthropological changes, it is necessary to provide an integrative approach for the prevention and control of metal pollution, in order to limit its impact on water resources, biodiversity, trophic network and human health. For this purpose, introduction of constructed wetlands (CWs) between natural aquatic ecosystems and industrialised zones or catchments is a promising strategy for eco-remediation. Analysis of the literature has shown that further research must be done to improve CW design, selection and management of wetland plant species and catchment organisation, in order to ensure the effectiveness of CWs in Mediterranean environments. Firstly, the parameters of basin design that have the greatest influence on metal removal processes must be identified, in order to better focus rhizospheric processes on specific purification objectives. We have summarised in a single diagram the relationships between the design parameters of a CW basin and the physico-chemical and biological processes of metal removal, on the basis of 21 mutually consistent papers. Secondly, in order to optimise the selection and distribution of helophytes in CWs, it is necessary to identify criteria of choice for the plant species that will best fit the remediation objectives and environmental and economic constraints. We have analysed the factors determining plant metal uptake efficiency in CWs on the basis of a qualitative meta-analysis of 13 studies with a view to determine whether the part played by metal uptake by plants is relevant in comparison with the other removal processes. Thirdly, we analysed the parameters to consider for establishing suitable management strategies for CWs and how they affect the whole CW design process

  8. Including impacts of particulate emissions on marine ecosystems in life cycle assessment: the case of offshore oil and gas production.

    Science.gov (United States)

    Veltman, Karin; Huijbregts, Mark A J; Rye, Henrik; Hertwich, Edgar G

    2011-10-01

    contribution of particulate emissions to the total impact on the marine water column is of minor importance. We conclude that particles are an important stressor in marine ecosystems, particularly for marine sediment, and particulate emissions should therefore be included in a (life cycle) impact assessment of offshore oil and gas production.

  9. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  10. Long-term impacts of forest ditching on non-aquatic biodiversity: conservation perspectives for a novel ecosystem.

    Science.gov (United States)

    Remm, Liina; Lõhmus, Piret; Leis, Mare; Lõhmus, Asko

    2013-01-01

    Artificial drainage (ditching) is widely used to increase timber yield in northern forests. When the drainage systems are maintained, their environmental impacts are likely to accumulate over time and along accompanying management, notably after logging when new forest develops on decayed peat. Our study provides the first comprehensive documentation of long-term ditching impacts on terrestrial and arboreal biodiversity by comparing natural alder swamps and second-generation drained forests that have evolved from such swamps in Estonia. We explored species composition of four potentially drainage-sensitive taxonomic groups (vascular plants, bryophytes, lichens, and snails), abundance of species of conservation concern, and their relationships with stand structure in two-ha plots representing four management types (ranging from old growth to clearcut). We found that drainage affected plot-scale species richness only weakly but it profoundly changed assemblage composition. Bryophytes and lichens were the taxonomic groups that were most sensitive both to drainage and timber-harvesting; in closed stands they responded to changed microhabitat structure, notably impoverished tree diversity and dead-wood supply. As a result, natural old-growth plots were the most species-rich and hosted several specific species of conservation concern. Because the most influential structural changes are slow, drainage impacts may be long hidden. The results also indicated that even very old drained stands do not provide quality habitats for old-growth species of drier forest types. However, drained forests hosted many threatened species that were less site type specific, including early-successional vascular plants and snails on clearcuts and retention cuts, and bryophytes and lichens of successional and old forests. We conclude that three types of specific science-based management tools are needed to mitigate ditching effects on forest biodiversity: (i) silvicultural techniques to

  11. Long-term impacts of forest ditching on non-aquatic biodiversity: conservation perspectives for a novel ecosystem.

    Directory of Open Access Journals (Sweden)

    Liina Remm

    Full Text Available Artificial drainage (ditching is widely used to increase timber yield in northern forests. When the drainage systems are maintained, their environmental impacts are likely to accumulate over time and along accompanying management, notably after logging when new forest develops on decayed peat. Our study provides the first comprehensive documentation of long-term ditching impacts on terrestrial and arboreal biodiversity by comparing natural alder swamps and second-generation drained forests that have evolved from such swamps in Estonia. We explored species composition of four potentially drainage-sensitive taxonomic groups (vascular plants, bryophytes, lichens, and snails, abundance of species of conservation concern, and their relationships with stand structure in two-ha plots representing four management types (ranging from old growth to clearcut. We found that drainage affected plot-scale species richness only weakly but it profoundly changed assemblage composition. Bryophytes and lichens were the taxonomic groups that were most sensitive both to drainage and timber-harvesting; in closed stands they responded to changed microhabitat structure, notably impoverished tree diversity and dead-wood supply. As a result, natural old-growth plots were the most species-rich and hosted several specific species of conservation concern. Because the most influential structural changes are slow, drainage impacts may be long hidden. The results also indicated that even very old drained stands do not provide quality habitats for old-growth species of drier forest types. However, drained forests hosted many threatened species that were less site type specific, including early-successional vascular plants and snails on clearcuts and retention cuts, and bryophytes and lichens of successional and old forests. We conclude that three types of specific science-based management tools are needed to mitigate ditching effects on forest biodiversity: (i silvicultural

  12. Review of the Foreign and Domestic Research Progress in the Mercury in the Aquatic Ecosystem%关于水生生态系统中汞的国内外研究进展评述

    Institute of Scientific and Technical Information of China (English)

    武岳; 林清

    2015-01-01

    本文介绍了国内外对于水生生态系统中汞的生物地球化学循环研究的各项进展,从汞对水生动植物的毒性、汞的迁移转化、甲基汞的形成以及甲基汞对食物链及人体健康的影响等几方面进行评述。%This paper introduces the foreign and domestic research progress in the biogeochemical cycle of the mercury in the aquatic ecosystem, and makes a comprehensive review of mercury′s toxicity to aquatic macrophyte, mercury′s migration and transformation, the formation of methyl, and methyl′s impacts on the food chain and human health.

  13. 上海乡土水生植物资源及其在水生态恢复与水景观建设中的应用潜力%SURVEY OF NATIVE AQUATIC VASCULAR PLANTS AND ITS POTENTIAL APPLICATION FOR RESTORATION AND RECONSTRUCTION OF AQUATIC ECOSYSTEMS IN SHANGHAI

    Institute of Scientific and Technical Information of China (English)

    王婕; 张净; 达良俊

    2011-01-01

    水生植物作为水生生态系统的主体,对发挥水生生态系统的自维持、自循环功能有重要作用.研究通过相关资料的查阅,建立上海地区乡土水生植物名录,并对其科属组成、区系特征、生活型、生长型等进行统计分析.结果表明上海地区乡土水生植物共计35科83属160种(含变种),单属科、单种属的比例较高,均达65%以上;植物区系组成丰富、成分复杂,以热带成分占优势,达64.6%;生活型以挺水植物为主,沉水植物次之,浮水植物最少;生长型类型丰富,以草本型、禾草型居多,20种生长型可进一步归为表征相似生态学特征和功能地位的6个生长型组.在水生态恢复与水景观建设中,仅有68.8%的景观水体有水生植物应用,且应用种类在2种以下的占79.2%.乡土水生植物应用不足,一半以上为观赏性强的外来物种,应用频率较高的为挺水植物,对具有良好净化效果的沉水植物重视不够.因此,在水生态恢复与水景观建设中,建议加强乡土水生植物资源的繁育栽培,在充分利用乡土水生植物资源配置群落的基础上,根据水质的富营养及基底状况,通过不同生长型组水生植物的应用,构建“沉水-浮水-挺水”植物群落复合体,并通过“近自然型”护岸的营造,形成“水生-湿生”复合生态系统.运用植被工程学的原理和方法,采用“生态浮岛”、“生态沉岛”等技术营造水生植被,将强人工化的水景观建成具生命的水生生态系统.%With the rapid economical development, more and more degraded aquatic ecosystems can not be restored by themselves after they were polluted seriously. Aquatic vascular plant especially the native species, as an important component, play a significant role for implication of self-sustainable and self-circulation in aquatic ecosystems. Reconstruction and restoration of aquatic plants and vegetations is vital to construct the artificial

  14. Aquatic Macrophyte Risk Assessment for Pesticides

    NARCIS (Netherlands)

    Maltby, L.; Arnold, D.; Arts, G.H.P.; Davies, J.; Heimbach, F.; Pickl, C.; Poulsen, V.

    2009-01-01

    Given the essential role that primary producers play in aquatic ecosystems, it is imperative that the potential risk of pesticides to the structure and functioning of aquatic plants is adequately assessed. This book discusses the assessment of the risk of pesticides with herbicidal activity to aquat

  15. 应用生物完整性指数评价水生态系统健康的研究进展%Research progress on using index of biological integrity to assess aquatic ecosystem health

    Institute of Scientific and Technical Information of China (English)

    廖静秋; 黄艺

    2013-01-01

    Index of biological integrity (IBI) is one of the most important and popular tools in as-sessing aquatic ecosystem health. This paper reviewed the selection of indicator species for IBI, its construction process, and its applications in assessing aquatic ecosystem health, summarized the commonly used candidate biological parameter indices of fish-index of biological integrity (F-IBI), benthos-index of biological integrity (B-IBI) , and periphyton-index of biological integrity (P-IBI) , and pointed out the feasibility and necessity of using microbe-index of biological integrity (M-IBI) to assess the health of aquatic ecosystem.%生物完整性指数(IBI)法是评价水生态系统健康的一种重要且被广泛应用的方法.本文综述了生物完整性指数的指示物种选择原因、构建方法以及在水生态系统健康评价中的应用,并总结了现阶段生态系统评估常用的鱼类完整性指数(F-IBI)、底栖无脊椎动物完整性指数(B-IBI)和着生藻类完整性指数(P-IBI)中候选生物状况参数指标,提出了使用微生物完整性指数(M-IBI)评价水生态系统健康的可行性和必要性.

  16. Describing Anopheles arabiensis aquatic habitats in two riceland agro-ecosystems in Mwea, Kenya using a negative binomial regression model with a non-homogenous mean.

    Science.gov (United States)

    Jacob, Benjamin G; Griffith, Daniel; Muturi, Ephantus; Caamano, Erick X; Shililu, Josephat; Githure, John I; Novak, Robert J

    2009-01-01

    This research illustrates a geostatistical approach for modeling the spatial distribution patterns of Anopheles arabiensis Patton (Patton) aquatic habitats in two riceland environments. QuickBird 0.61 m data, encompassing the visible bands and the near-infra-red (NIR) band, were selected to synthesize images of An. arabiensis aquatic habitats. These bands and field sampled data were used to determine ecological parameters associated with riceland larval habitat development. SAS was used to calculate univariate statistics, correlations and Poisson regression models. Global autocorrelation statistics were generated in ArcGISfrom georeferenced Anopheles aquatic habitats in the study sites. The geographic distribution of Anopheles gambiae s.l. aquatic habitats in the study sites exhibited weak positive autocorrelation; similar numbers of log-larval count habitats tend to clustered in space. Individual rice land habitat data were further evaluated in terms of their covariations with spatial autocorrelation, by regressing them on candidate spatial filter eigenvectors. Each eigenvector generated from a geographically weighted matrix, for both study sites, revealed a distinctive spatial pattern. The spatial autocorrelation components suggest the presence of roughly 14-30% redundant information in the aquatic habitat larval count samples. Synthetic map pattern variables furnish a method of capturing spatial dependency effects in the mean response term in regression analyses of rice land An. arabiensis aquatic habitat data.

  17. Conceptual Framework for Aquatic Interfaces

    Science.gov (United States)

    Lewandowski, J.; Krause, S.

    2015-12-01

    Aquatic interfaces are generally characterized by steep gradients of physical, chemical and biological properties due to the contrast between the two adjacent environments. Innovative measurement techniques are required to study the spatially heterogeneous and temporally variable processes. Especially the different spatial and temporal scales are a large challenge. Due to the steep biogeochemical gradients and the intensive structural and compositional heterogeneity, enhanced biogeochemical processing rates are inherent to aquatic interfaces. Nevertheless, the effective turnover depends strongly on the residence time distribution along the flow paths and in sections with particular biogeochemical milieus and reaction kinetics. Thus, identification and characterization of the highly complex flow patterns in and across aquatic interfaces are crucial to understand biogeochemical processing along exchange flow paths and to quantify transport across aquatic interfaces. Hydrodynamic and biogeochemical processes are closely coupled at aquatic interfaces. However, interface processing rates are not only enhanced compared to the adjacent compartments that they connect; also completely different reactions might occur if certain thresholds are exceeded or the biogeochemical milieu differs significantly from the adjacent environments. Single events, temporal variability and spatial heterogeneity might increase overall processing rates of aquatic interfaces and thus, should not be neglected when studying aquatic interfaces. Aquatic interfaces are key zones relevant for the ecological state of the entire ecosystem and thus, understanding interface functioning and controls is paramount for ecosystem management. The overall aim of this contribution is a general conceptual framework for aquatic interfaces that is applicable to a wide range of systems, scales and processes.

  18. Retracted: Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems.

    Science.gov (United States)

    Wierda, Michael R; Leith, Katherine F; Grubb, Teryl G; Sikarskie, James G; Best, David A; Bowerman, William

    2016-08-01

    Retraction: 'Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems' by Michael R. Wierda, Katherine F. Leith, Teryl G. Grubb, James G. Sikarskie, David A. Best, and William Bowerman The above article from Environmental Toxicology and Chemistry, published online on 10 February 2015 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, G.A. Burton, Jr., SETAC and Wiley Periodicals, Inc. The retraction has been agreed since the authors determined that some of the plasma samples run at Clemson University had failed quality assurance/quality control and were retested. The concentrations have since been corrected and validated. Reference Wierda MR, Leith KF, Grubb TG, Sikarskie JG, Best DA, Bowerman W. 2015. Using bald eagles to track spatial (1999-2008) and temporal (1987-1992, 1999-2003, and 2004-2008) trends of contaminants in Michigan's aquatic ecosystems. Environ ToxicolChem doi:10.1002/etc.2859.

  19. 大型底栖动物在水生态系统健康评价中的应用%The application of benthic macroinvertebrates in aquatic ecosystem health assessment

    Institute of Scientific and Technical Information of China (English)

    王艳杰; 李法云; 范志平; 程志辉; 张建祺

    2012-01-01

    Benthic macroinvertebrates are the main components of the aquatic ecosystem and play a key role in function and health of aquatic ecosystem.With the increasing emphasis on the aquatic ecosystem management based on watershed integrity in China,the studies on aquatic ecosystem health is more and more detailed,thus the study of benthic macroinvertebrates are improved not only in depth but also in breadth.The main study tasks,impacting factors and analytical methods on benthic macroinvertebrates were summarized at home and abroad in recent years.The results indicate that the response of benthic macroinverebrates to the variation of aquatic ecosystem is significant on the spatial scale,so the effects of natural environment,habitat conditions and water quality on benthic animal diversity and its community structure in the different spatial scales were analyzed.The variations of water environment factors caused by the human activities or the damage of habitat could influence directly the species composition and community features of benthic animal according to the integrated analysis of various factors.The analytical methods on benthic animal could be classified as two types,namely,a model analytical method and a biology index assessment method.Which one is selected in the actual application depends on the features of model and index.%大型底栖动物是维系水生态系统结构和功能的重要组成部分,也是影响水生态系统健康与功能的重要水生生物指标。随着中国对基于流域完整性水生态管理的日益重视,水生态系统健康的研究也更加深入,因而底栖动物的研究在深度和广度上均有所提高。概述了近年来国内外底栖动物的主要研究方向、影响因素及其分析方法。结果表明:在研究方向上,由于底栖动物对水生态系统变化的响应具有明显的空间尺度效应,因而以不同尺度空间上的自然环境、生境条件和水质等因子为分界,分析其对底

  20. Applications of eco-exergy in ecological modeling and assessment of aquatic ecosystems%生态能质(eco-exergy)在水生生态系统建模和评价中的应用

    Institute of Scientific and Technical Information of China (English)

    李晴新; 冯剑丰; 朱琳

    2011-01-01

    Eco-exergy is defined as the amount of work that a system can perform when the system is brought into thermodynamic equilibrium from a given state.It can be used to measure the complex biochemical components and ecological structure.A system with more exergy will present better ordering and stability.Eco-exergy and specific eco-exergy can be used to assess the status of aquatic ecosystem health, and indicate the certain succession stage in aquatic ecosystem restoration.This paper presented the definitions and ecological meanings of eco-exergy and specific eco-exergy as well as the calculation methods of eco-exergy and weighting factor fi, summarized the applications of eco-exergy as a goal function in structural dynamic models (SDMs) and as an ecological indicator for ecosystem health assessment and ecological restoration of aquatic ecosystems, and discussed the limitations and future development of eco-exergy.Furthermore,the unified translation of "eco-exergy" and "specific eco-exergy" in Chinese was suggested.%生态能质(eco-exergy)是指系统从给定状态达到热力学平衡状态所做的功,可以度量生态系统的复杂生物化学组分及生态结构.系统具有的能质越大,有序化程度越高,稳定性也越强.生态能质和比生态能质(specific eco-exergy)指标能够评价水生生态系统健康状况,对水生生态系统演替阶段具有指示作用.本文阐述了生态能质的定义、生态学意义以及生态能质值和权重因子fi值的计算方法.对生态能质作为功能函数在水生生态系统结构动力学模型(structural dynamic models,SDMs)中以及作为生态指标在生态系统健康评价、生态恢复研究中的实际应用进行了总结.最后探讨了生态能质指标的局限性以及未来的发展.此外,文中建议将"eco-exergy"和"specific eco-exergy"统一翻译为"生态能质"和"比生态能质".

  1. Risk and markets for ecosystem services.

    Science.gov (United States)

    Bendor, Todd K; Riggsbee, J Adam; Doyle, Martin

    2011-12-15

    Market-based environmental regulations (e.g., cap and trade, "payments for ecosystem services") are increasingly common. However, few detailed studies of operating ecosystem markets have lent understanding to how such policies affect incentive structures for improving environmental quality. The largest U.S. market stems from the Clean Water Act provisions requiring ecosystem restoration to offset aquatic ecosystems damaged during development. We describe and test how variations in the rules governing this ecosystem market shift risk between regulators and entrepreneurs to promote ecological restoration. We analyze extensive national scale data to assess how two critical aspects of market structure - (a) the geographic scale of markets and (b) policies dictating the release of credits - affect the willingness of entrepreneurs to enter specific markets and produce credits. We find no discernible relationship between policies attempting to ease market entry and either the number of individual producers or total credits produced. Rather, market entry is primarily related to regional geography (the prevalence of aquatic ecosystems) and regional economic growth. Any improvements to policies governing ecosystem markets require explicit evaluation of the interplay between policy and risk elements affecting both regulators and entrepreneurial credit providers. Our findings extend to emerging, regulated ecosystem markets, including proposed carbon offset mechanisms, biodiversity banking, and water quality trading programs.

  2. Biotransformation and accumulation of selenium inside organisms in an engineered aquatic ecosystem designed for bioremediation of Se from agriculture drainage water and brine shrimp production

    Science.gov (United States)

    Excessive selenium (Se) in soils and waters present in the westside of central California was determined to be responsible for ecotoxicities observed in water fowl frequenting large bodies of water, i.e., evaporation ponds. In order to monitor the fate and potentially design an aquatic Se remediatio...

  3. The use of enclosed plankton communities in aquatic ecotoxicology : fate effects of mercury, cadmium and selected aromatic organics in a marine model ecosystem

    NARCIS (Netherlands)

    Kuiper, J.

    1982-01-01

    Most investigations in ecotoxicology are carried out in the laboratory. Although laboratory experiments are indispensable and yield useful information, it is difficult if not impossible to extrapolate results of short-term laboratory tests currently in use to real field situations. The need in aquat

  4. Why Care About Aquatic Insects: Uses, Benefits, and Services

    Science.gov (United States)

    Mayflies and other aquatic insects are common subjects of ecological research, and environmental monitoring and assessment. However, their important role in protecting and restoring aquatic ecosystems is often challenged, because their benefits and services to humans are not obv...

  5. Introduced aquatic plants and algae

    Science.gov (United States)

    Non-native aquatic plants such as waterhyacinth and hydrilla severely impair the uses of aquatic resources including recreational faculties (lakes, reservoirs, rivers) as well as timely delivery of irrigation water for agriculture. Costs associated with impacts and management of all types of aquatic...

  6. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  7. Evaluation of Aquatic Ecosystem Service Value of the Rivers and Reservoirs Connection Project in Ji′nan City%济南市河库连通工程水生态系统服务价值评估

    Institute of Scientific and Technical Information of China (English)

    解文静; 茅樵; 曹升乐

    2015-01-01

    The aquatic ecosystem service value of the rivers and reservoirs connection project in Ji′nan City was divided into four parts:providing product function,regulating function,cultural function and life support function. The direct market value method,shadow engineering method,replacement cost method,carbon tax method and assets value method were used to evaluate the aquatic ecosystem service value of the rivers and reservoirs connection project in Ji′nan City. The results show that the rivers and reservoirs system of ecological service value in Ji′nan City is diverse and of great value,especially remarkable in the living environment,the function of leisure tourism and the function of water supply. This conclusion conforms to the actual situation of Ji′nan City,and the evaluation results are reasonable.%将济南市河库连通工程河库水系生态系统服务功能分为提供产品功能、调节功能、文化功能和生命支持功能4类,采用直接市场评价法、影子价格法、替代费用法、碳税法、费用支出法等方法评估了该工程的生态服务价值。结果表明:济南市河库系统生态服务价值多样,且价值巨大,尤其是发挥人居环境功能、休闲旅游功能、水供给功能的价值,评估结果符合济南市实际情况。

  8. Inland Aquatic Resources and Biogeochemical Cycles

    Science.gov (United States)

    Melack, J. M.

    1984-01-01

    The biosphere is the entire planetary system that includes, sustains and is influenced by life. The central issue of the science of the biosphere is the extent to which the Earth's surface, atmosphere and hydrosphere is the result of biological rather than abiotic processes. Space science and technology accelerates the understanding of global biological processes by providing repetive synoptic observations on large spatial scales once the relationships between the processes and the remotely sensed quantities are established. Especially promising applications of space technology are the measurement of biological productivity and portions of geochemical cycles in aquatic ecosystems and the evaluation and management of the quality of freshwater resources.

  9. FABM-PCLake - linking aquatic ecology with hydrodynamics

    Science.gov (United States)

    Hu, Fenjuan; Bolding, Karsten; Bruggeman, Jorn; Jeppesen, Erik; Flindt, Morgens R.; van Gerven, Luuk; Janse, Jan H.; Janssen, Annette B. G.; Kuiper, Jan J.; Mooij, Wolf M.; Trolle, Dennis

    2016-07-01

    This study presents FABM-PCLake, a redesigned structure of the PCLake aquatic ecosystem model, which we implemented in the Framework for Aquatic Biogeochemical Models (FABM). In contrast to the original model, which was designed for temperate, fully mixed freshwater lakes, the new FABM-PCLake represents an integrated aquatic ecosystem model that can be linked with different hydrodynamic models and allows simulations of hydrodynamic and biogeochemical processes for zero-dimensional, one-dimensional as well as three-dimensional environments. FABM-PCLake describes interactions between multiple trophic levels, including piscivorous, zooplanktivorous and benthivorous fish, zooplankton, zoobenthos, three groups of phytoplankton and rooted macrophytes. The model also accounts for oxygen dynamics and nutrient cycling for nitrogen, phosphorus and silicon, both within the pelagic and benthic domains. FABM-PCLake includes a two-way communication between the biogeochemical processes and the physics, where some biogeochemical state variables (e.g., phytoplankton) influence light attenuation and thereby the spatial and temporal distributions of light and heat. At the same time, the physical environment, including water currents, light and temperature influence a wide range of biogeochemical processes. The model enables studies on ecosystem dynamics in physically heterogeneous environments (e.g., stratifying water bodies, and water bodies with horizontal gradients in physical and biogeochemical properties), and through FABM also enables data assimilation and multi-model ensemble simulations. Examples of potential new model applications include climate change impact studies and environmental impact assessment scenarios for temperate, sub-tropical and tropical lakes and reservoirs.

  10. ZOONOSIS OF AQUATICAL ORGANISMS

    OpenAIRE

    2001-01-01

    Aquatic organisms play a very important role in human nutrition. They also pose a real threat for human health by causing various diseases. Parasites, bacteria and viruses may either directly or indirectly be carried from aquatic organisms to humans. Disease outbreaks are influenced by many factors among which decreased immune response and feeding habits and higyene are most important. More frequent occuence of foodborne diseases has a number of reasons, including international travel and tra...

  11. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Johansen, Jacob L

    2014-01-01

    Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (reef system around Lizard Island (Great Barrier Reef, Australia) at a spatial and temporal scale relevant to the ecology of individual benthos and fish. The instrument uses load-cell sensors to provide a correlation between sensor output and ambient current velocity of 99%. Each instrument is able to continuously record current velocities to >500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.). Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m), mid-slope (6 m) and deep-slope (9 m depth) of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m) and frequency (0.54 to 0.20 Hz), emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  12. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Jacob L Johansen

    Full Text Available Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.. Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m, mid-slope (6 m and deep-slope (9 m depth of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m and frequency (0.54 to 0.20 Hz, emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  13. Caffeine as an environmental indicator for assessing urban aquatic ecosystems Cafeína como indicador ambiental prospectivo para avaliar ecossistemas aquáticos urbanos

    Directory of Open Access Journals (Sweden)

    Aldo Pacheco Ferreira

    2005-12-01

    Full Text Available This study aimed to evaluate the co-occurrence of caffeine and the extent of its influence as compared to other traditional water quality parameters (microbiological and physico-chemical in order to characterize it as an efficient indicator of anthropic pollution of urban aquatic environments. Caffeine is an ingredient in a variety of beverages (coffee, tea, and caffeinated soft drinks and numerous food products (chocolate, pastries, and dairy desserts. Although the human body metabolizes this stimulant efficiently, between 0.5 and 10.0% is excreted, mostly in the urine. Analysis of water samples from the Leopoldina Basin and Guanabara Bay revealed a significant difference between areas not commonly affected by nutrient enrichment or sewage inputs and areas chronically influenced by sewage discharges and elevated eutrophication. Monitoring caffeine will be fundamental in stressed urban aquatic environments where frequent accidental ruptures of sewer lines and discharges of untreated effluents impede effective water quality evaluation with traditional indicators.Este estudo visou avaliar a co-ocorrência de cafeína e a extensão de sua influência frente a outros parâmetros tradicionais de qualidade de água (microbiológicos e físico-químicos, de modo a caracterizá-la como um eficiente indicador de poluição de origem antrópica em ambientes aquáticos urbanos. Cafeína é um componente de uma variedade de bebidas (café, chá e bebidas cafeinadas e de numerosos produtos alimentícios (chocolate, massas e sobremesas. Embora o corpo humano seja eficiente na metabolização deste estimulante, entre 0,5-10,0% são excretados, principalmente na urina. A análise de amostras da Bacia Hidrográfica da Leopoldina e Baía de Guanabara, Rio de Janeiro, Brasil, revelou uma significante diferença entre áreas não comumente afetadas por enriquecimento de nutrientes ou esgoto, contra áreas cronicamente influenciadas por descargas de esgoto e

  14. An integrated approach to model the biomagnification of organic pollutants in aquatic food webs of the Yangtze Three Gorges Reservoir ecosystem using adapted pollution scenarios.

    Science.gov (United States)

    Scholz-Starke, Björn; Ottermanns, Richard; Rings, Ursula; Floehr, Tilman; Hollert, Henner; Hou, Junli; Li, Bo; Wu, Ling Ling; Yuan, Xingzhong; Strauch, Katrin; Wei, Hu; Norra, Stefan; Holbach, Andreas; Westrich, Bernhard; Schäffer, Andreas; Roß-Nickoll, Martina

    2013-10-01

    The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aquacultures, and households. The main aim of the presented research project is a deeper understanding of the processes that determines the bioaccumulation and biomagnification of organic pollutants, i.e., mainly pesticides, in aquatic food webs under the newly developing conditions of the TGR. The project is part of the Yangtze-Hydro environmental program, financed by the German Ministry of Education and Science. In order to test combinations of environmental factors like nutrients and pollution, we use an integrated modeling approach to study the potential accumulation and biomagnification. We describe the integrative modeling approach and the consecutive adaption of the AQUATOX model, used as modeling framework for ecological risk assessment. As a starting point, pre-calibrated simulations were adapted to Yangtze-specific conditions (regionalization). Two exemplary food webs were developed by a thorough review of the pertinent literature. The first typical for the flowing conditions of the original Yangtze River and the Daning River near the city of Wushan, and the second for the stagnant reservoir characteristics of the aforementioned region that is marked by an intermediate between lake and large river communities of aquatic organisms. In close cooperation with German and Chinese partners of the Yangtze-Hydro Research Association, other site-specific parameters were estimated. The MINIBAT project contributed to the calibration of physicochemical and bathymetric parameters, and the TRANSMIC project delivered

  15. Progresses on the InteraCtion between Selenium and MerCury in an AquatiC ECosystem%水生生态系统中汞-硒相互作用研究进展

    Institute of Scientific and Technical Information of China (English)

    南雪娇; 余晓平; 郭金玲; 郭亚飞; 邓天龙

    2016-01-01

    Methylmercury is the most toxic form among mercury compounds in the aquatic ecosystem,and poses health risks to organisms through the food chain. The effective control of methylation processes of mercury is an active research field in environmental chemistry and toxicology. Selenium(Se)has a significant suppression effect on the methylation processes of mercury(Hg). Therefore,it will be beneficial to the prevention and control of mercury contamination to clarify the speciation characteristic of mercury and the interaction mechanisms between mercury and selenium in the aquatic ecosystem. Mercury toxicity is closely associated with the levels of selenium in organisms,the interaction between Hg and Se are mainly embodied in the formation of insoluble compounds to contribute mercury demethylation or methylmercury directly ruled out by inhibition of biological a selenium related enzyme,which inhibits the toxic effect of mercury. In this paper,the speciation and distribution characteristics of mercury and selenium in the aquatic ecosystem and their interaction mechanisms were reviewed. Meanwhile,the reasonable addition of selenium compounds into water will be an effective way to inhibit the methylation processes of mercury in organisms. The development direction for the studies of interaction mechanisms between mercury and selenium and its physical effects in organisms were also reviewed.%甲基汞是汞存在于水生生态系统(水体、沉积物和水生生物)毒性最强的形态,并通过食物链的传递对生物体产生危害,因此有效控制汞的甲基化过程是汞环境化学和毒理学研究的重要课题.生物体内硒对汞的甲基化过程有明显的抑制作用,明确汞和硒在水生生态系统的形态特征以及汞 - 硒相互作用机制,有助于解决汞污染问题.汞在生物体内的毒性与生物体内硒含量紧密相关,汞与硒相之间的相互作用主要表现在生成不溶的化合物促使汞去甲基化或受生物

  16. The C.E.B.A. Mini Module on the STS-107 Mission: Data of Ground Experiments and Preliminary Results of the third Spaceflight of an Artificial Aquatic Ecosystem

    Science.gov (United States)

    Bluem, V.; Paris, F.; Bungart, S.

    The C.E.B.A.S MINI MODULE is the miniaturized version of an artificial aquatic ecosystem consisting of four subcomponents: a ZOOLOGICAL COMPONENT (aquarium for animals), a BOTANICAL COMPONENT (higher water plant bioreactor), a MICROBIAL COMPONENT (bacteria filter) and an ELECTRONICAL COMPONENT (data acquisition, control unit). It has a total volume of 8.6 liters and contains the ovoviviparous teleost Xiphophorus helleri (swordtail), larvae of the ovuliparous cichlid fish Oreochromis mossambicus, the pulmonate water snail Biomphalaria glabrata, the rootless (non-graivitropic) higher water plant Ceratophyllum demersum (hornweed) and special strains of ammonia oxidizing bacteria. This device was already flown twice successfully in space with the space shuttle missions STS- 89 and STS-90 (NEUROLAB) in 1998. It will fly a third time with the STS-107-mission the launch of which has been repeatedly shifted December 222, April 2001, October 2001) and is now finally scheduled for June 2002. The main focus of scientific interest in the past missions were system performance, reproductive biology (reproductive function of adult females including endocrine system, fertilization, gonadal development in juveniles), vestibular and immunological research in X. helleri, embryology and shell formation in B. glabrata, general morphology and physiology of C. demersum and groth rates of the bacteria. The standard load of the system were 4 adult and 200 neonate X. helleri, 30 adult B. glabrata and 30 g of C. demersum. The evaluation of these experiments showed that all reproductive functions and the immune system of the fishes snails remained undisturbed in space, that the snails developed normally and exhibited no disturbance of shell formation and that the plants showed growth and photosynthesis rates comparable to those on Earth. So, as a logical continuation, the main topics for the STS-107 mission are the remaining important questions in X. helleri biology: puberty, male sexual

  17. Pesticide and PCB residues in the aquatic ecosystems of Laguna de Terminos, a protected area of the coast of Campeche, Mexico.

    Science.gov (United States)

    Carvalho, Fernando P; Villeneuve, Jean-Pierre; Cattini, C; Rendón, Jaime; Mota de Oliveira, J

    2009-02-01

    The coastal lagoon system of Laguna de Terminos, Campeche, Mexico, a natural reserve since 1994, was investigated for contamination by agricultural and industrial chemical residues. Water, sediment and biota samples were analyzed for a wide variety of organochlorine and organophosphorus compounds. Chlorpyrifos was detected in water in concentrations up to 72 pgL(-1) and, amongst organochlorine compounds, summation operator PCB were measured averaging 1177 pgL(-1) and summation operator DDT 279 pgL(-1). Residues of chlorinated compounds were present in sediments and in biota with summation operator DDT averaging 190 pg g(-1) and 5876 pg g(-1) in sediment and oysters, respectively. Results show that the more widespread contaminants in the Laguna were residues of chlorinated hydrocarbons, such as DDTs, PCBs, endosulfan, and lindane. Concentrations of residues were not at an alarming level and were even lower than reported for other costal lagoons of the region. Still there is a need to implement control measures on persistent and bioaccumulative compounds that may reach the aquatic system of Laguna de Terminos.

  18. Isotopic evidence for anthropogenic impacts on aquatic food web dynamics and mercury cycling in a subtropical wetland ecosystem in the US

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang, E-mail: ywang@magnet.fsu.edu [Department of Earth, Ocean and Atmospheric Science, Florida State University and National High Magnetic Field Laboratory, Tallahassee, FL 32306–4100 (United States); Gu, Binhe [South Florida Water Management District, West Palm Beach, FL 33406 (United States); Lee, Ming-Kuo [Department of Geology and Geography, Auburn University, Auburn, AL 36839 (United States); Jiang, Shijun, E-mail: sjiang@jnu.edu.cn [Institute of Hydrobiology/Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, Guangdong 510632 (China); Xu, Yingfeng [Department of Earth, Ocean and Atmospheric Science, Florida State University and National High Magnetic Field Laboratory, Tallahassee, FL 32306–4100 (United States)

    2014-07-01

    Quantifying and predicting the food web consequences of anthropogenic changes is difficult using traditional methods (based on gut content analysis) because natural food webs are variable and complex. Here, stable and radioactive carbon isotopes are used, in conjunction with nitrogen isotopes and mercury (Hg) concentration data, to document the effects of land-use change on food webs and Hg bioaccumulation in the Everglades – a subtropical wetland ecosystem in the US. Isotopic signatures of largemouth bass and sunfish in reference (relatively pristine) wetlands indicate reliance on the food supply of modern primary production within the wetland. In contrast, both fish in areas impacted by agricultural runoff had radiocarbon ages as old as 540 years B.P., and larger isotopic variability than counterparts in reference wetlands, reflecting differences in the food web between impacted and reference wetlands. Consistent with this difference, particulate and dissolved organic matter in impacted areas had old radiocarbon ages (> 600 years B.P.), indicating that old carbon derived from historic peat deposits in the Everglades Agricultural Area was passed along the food chain to consumers. Significant radiocarbon deficiencies in largemouth bass and sunfish, relative to mosquitofish, in impacted areas most likely indicate a reduced dependence on small fish. Furthermore, largemouth bass and sunfish from impacted areas had much lower Hg contents than those from reference wetlands. Taken together, these data suggest a shift toward lower trophic levels and a possible reduction in mercury methylation in impacted wetlands. Our study provides clear evidence that hydrological modification and land-use change in the Everglades have changed the system from one driven primarily by in-situ productivity to one that is partially dependent on allochthonous carbon input from peat soils in the agricultural area and altered the Hg biogeochemical cycle in the wetlands. The results have

  19. Impact of Volcanic Eruptions on the Occurrence of PAHs Compounds in the Aquatic Ecosystem of the Southern Part of West Spitsbergen (Hornsund Fjord, Svalbard

    Directory of Open Access Journals (Sweden)

    Katarzyna Kozak

    2017-01-01

    Full Text Available The paper presents changes in concentration levels of dioxin-like compounds that can be observed over the course of four study seasons in water samples collected from the Arctic watershed of Svalbard. The conducted analysis involved anthropogenic and natural factors that may affect the concentration of PAHs in the study samples of water. An attempt is made to indicate the emission source of the compounds being deposited and to identify the extent to which the substances under analysis actually affect the Arctic ecosystems. Moreover, the work employs the following: diagnostic ratios PAHs, air masses backward trajectory analysis, Lidar observations and land relief analysis in order to provide a multi-level interpretation of the obtained data. Natural environment constitutes a complex system of subtle correlations that need to be perceived as a dynamic medium, in which multi-faceted processes take place.

  20. Isotopic evidence for anthropogenic impacts on aquatic food web dynamics and mercury cycling in a subtropical wetland ecosystem in the US.

    Science.gov (United States)

    Wang, Yang; Gu, Binhe; Lee, Ming-Kuo; Jiang, Shijun; Xu, Yingfeng

    2014-07-15

    Quantifying and predicting the food web consequences of anthropogenic changes is difficult using traditional methods (based on gut content analysis) because natural food webs are variable and complex. Here, stable and radioactive carbon isotopes are used, in conjunction with nitrogen isotopes and mercury (Hg) concentration data, to document the effects of land-use change on food webs and Hg bioaccumulation in the Everglades - a subtropical wetland ecosystem in the US. Isotopic signatures of largemouth bass and sunfish in reference (relatively pristine) wetlands indicate reliance on the food supply of modern primary production within the wetland. In contrast, both fish in areas impacted by agricultural runoff had radiocarbon ages as old as 540 years B.P., and larger isotopic variability than counterparts in reference wetlands, reflecting differences in the food web between impacted and reference wetlands. Consistent with this difference, particulate and dissolved organic matter in impacted areas had old radiocarbon ages (>600 years B.P.), indicating that old carbon derived from historic peat deposits in the Everglades Agricultural Area was passed along the food chain to consumers. Significant radiocarbon deficiencies in largemouth bass and sunfish, relative to mosquitofish, in impacted areas most likely indicate a reduced dependence on small fish. Furthermore, largemouth bass and sunfish from impacted areas had much lower Hg contents than those from reference wetlands. Taken together, these data suggest a shift toward lower trophic levels and a possible reduction in mercury methylation in impacted wetlands. Our study provides clear evidence that hydrological modification and land-use change in the Everglades have changed the system from one driven primarily by in-situ productivity to one that is partially dependent on allochthonous carbon input from peat soils in the agricultural area and altered the Hg biogeochemical cycle in the wetlands. The results have

  1. Single particle ICP-MS as a tool for determining the stability of silver nanoparticles in aquatic matrixes under various environmental conditions, including treatment by ozonation.

    Science.gov (United States)

    Telgmann, Lena; Nguyen, Michael Thanh Khoa; Shen, Li; Yargeau, Viviane; Hintelmann, Holger; Metcalfe, Chris D

    2016-07-01

    Silver nanoparticles (AgNPs) are used in a large number of consumer products due to their antimicrobial and antifungal properties, and these materials may be discharged into municipal wastewater. Wastewater treatment, including advanced oxidation processes (AOPs), may modify the forms of silver in wastewater before they are discharged into surface waters. In addition, little is known about the changes in AgNPs that occur in natural waters under different environmental conditions. In this project, we utilized single particle ICP-MS (spICP-MS) and dynamic light scattering (DLS) analytical techniques to evaluate changes in the number and size of AgNPs in laboratory experiments with milliQ water under different environmental conditions, as well as during ozonation. Changes in the number and size of AgNPs determined by spICP-MS were evidence of altered stability of the nanoparticles. Increased rates of dissolution occurred under extremes of pH. Lower temperature decreased the rate of dissolution of AgNP relative to the dissolution in treatments at room temperature. The addition of chloride resulted in the loss of AgNPs from suspension due to agglomeration and precipitation. Ozonation led to a rapid decline in the number and size of AgNPs, as indicated by both spICP-MS and DLS analysis. An increase in the concentration of dissolved silver in the ozone treatments was evidence that changes in particle size were a result of oxidative dissolution of AgNPs to silver ion. Graphical abstract Single particle ICP-MS is used to evaluate dissolution of silver nanoparticles under different environmental conditions, including water treatment by ozonation.

  2. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting.

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P; Clow, David W; Striegl, Robert G

    2016-01-01

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71-149) teragrams of carbon per year (TgC⋅y(-1)) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9-65) TgC⋅y(-1) in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36-110) TgC⋅y(-1) or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass-flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.

  3. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P.; Clow, David W.; Striegl, Robert G.

    2016-01-01

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1 or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity. PMID:26699473

  4. The role of storm flows in concentration of pesticides associated with particulate and dissolved fractions as a threat to aquatic ecosystems - Case study: the agricultural watershed of Save river (Southwest of France

    Directory of Open Access Journals (Sweden)

    Taghavi L.

    2011-02-01

    Full Text Available Measurement of the fluxes of pesticides was carried out for a year, ending in March 2009, in the Save catchment, in the vicinity of Toulouse. The hydrograph separation technique was used to evaluate the respective contribution of stormflow and baseflow in transport of 12 pesticide molecules. Transport of over 59% of pesticides and their controlling factors such as total suspended matter (TSM, particulate organic carbon (POC and dissolved organic carbon (DOC occurred during storm periods. Hysteresis patterns could be observed in the concentration-discharge relationships only for some molecules between rising and falling periods of the storm hydrograph. Clockwise hysteresis was noticed for low to moderately soluble pesticide molecules and for particulate fractions, which explains the role of surface runoff in pesticide displacement. In contrast, anticlockwise hysteresis was registered for soluble molecules and dissolved fractions, explaining the role of subsurface flows and soil leaching processes. The important role of TSM, POC and DOC in pesticide transport was clearly established. We also came to the conclusion that the role of stormy periods in pesticide movement and their controlling factors worked as a threat to aquatic ecosystems. And there was a positive relation between riverine TSM, POC, DOC and pesticides according to pesticide properties.

  5. Ecosystem services provided by waterbirds.

    Science.gov (United States)

    Green, Andy J; Elmberg, Johan

    2014-02-01

    Ecosystem services are ecosystem processes that directly or indirectly benefit human well-being. There has been much recent literature identifying different services and the communities and species that provide them. This is a vital first step towards management and maintenance of these services. In this review, we specifically address the waterbirds, which play key functional roles in many aquatic ecosystems, including as predators, herbivores and vectors of seeds, invertebrates and nutrients, although these roles have often been overlooked. Waterbirds can maintain the diversity of other organisms, control pests, be effective bioindicators of ecological conditions, and act as sentinels of potential disease outbreaks. They also provide important provisioning (meat, feathers, eggs, etc.) and cultural services to both indigenous and westernized societies. We identify key gaps in the understanding of ecosystem services provided by waterbirds and areas for future research required to clarify their functional role in ecosystems and the services they provide. We consider how the economic value of these services could be calculated, giving some examples. Such valuation will provide powerful arguments for waterbird conservation.

  6. Bioaccumulation and biomagnification potential of pharmaceuticals with a focus to the aquatic environment.

    Science.gov (United States)

    Zenker, Armin; Cicero, Maria Rita; Prestinaci, Francesca; Bottoni, Paola; Carere, Mario

    2014-01-15

    Pharmaceuticals, among the emerging contaminants, are one of the most relevant groups of substances in aquatic ecosystems due to universal use, their chemico-physical properties and known mode of action in aquatic organisms at low concentrations. After administration many drugs and their transformation products are only retained to some extent in wastewater treatment plants therefore entering the aquatic environment in considerable high amounts. The yearly consumption to treat human and animal diseases, also in livestock and aquaculture was estimated to be hundred thousands tons per year leading to high concentrations in surface water of developed countries. Mostly, pharmaceutical residues in effluents of wastewater treatment plants or in the water column of surface waters have been reported, but data about concentrations in the aquatic biota, partitioning of pharmaceuticals to biosolids, soils, and sediments and the bioaccumulation properties are often lacking. Chronic and subtle effects can be expected when aquatic organisms are long term exposed by pseudo-persistent, persistent and accumulative compounds. This review aims to summarize the current state of research about the fate of pharmaceuticals regarding bioconcentration, bioaccumulation and potential biomagnification in aquatic ecosystems. More comprehensive approaches for the evaluation of environmental (ERA) and human health risk assessment (HRA) are included and analytical methods required to detect bioaccumulation of pharmaceuticals are discussed.

  7. Proactive aquatic ecotoxicological assessment of room-temperature ionic liquids

    Science.gov (United States)

    Kulacki, K.J.; Chaloner, D.T.; Larson, J.H.; Costello, D.M.; Evans-White, M. A.; Docherty, K.M.; Bernot, R.J.; Brueseke, M.A.; Kulpa, C.F.; Lamberti, G.A.

    2011-01-01

    Aquatic environments are being contaminated with a myriad of anthropogenic chemicals, a problem likely to continue due to both unintentional and intentional releases. To protect valuable natural resources, novel chemicals should be shown to be environmentally safe prior to use and potential release into the environment. Such proactive assessment is currently being applied to room-temperature ionic liquids (ILs). Because most ILs are water-soluble, their effects are likely to manifest in aquatic ecosystems. Information on the impacts of ILs on numerous aquatic organisms, focused primarily on acute LC50 and EC50 endpoints, is now available, and trends in toxicity are emerging. Cation structure tends to influence IL toxicity more so than anion structure, and within a cation class, the length of alkyl chain substituents is positively correlated with toxicity. While the effects of ILs on several aquatic organisms have been studied, the challenge for aquatic toxicology is now to predict the effects of ILs in complex natural environments that often include diverse mixtures of organisms, abiotic conditions, and additional stressors. To make robust predictions about ILs will require coupling of ecologically realistic laboratory and field experiments with standard toxicity bioassays and models. Such assessments would likely discourage the development of especially toxic ILs while shifting focus to those that are more environmentally benign. Understanding the broader ecological effects of emerging chemicals, incorporating that information into predictive models, and conveying the conclusions to those who develop, regulate, and use those chemicals, should help avoid future environmental degradation. ?? 2011 Bentham Science Publishers Ltd.

  8. Multivariate and phylogenetic analyses assessing the response of bacterial mat communities from an ancient oligotrophic aquatic ecosystem to different scenarios of long-term environmental disturbance.

    Science.gov (United States)

    Pajares, Silvia; Souza, Valeria; Eguiarte, Luis E

    2015-01-01

    Understanding the response of bacterial communities to environmental change is extremely important in predicting the effect of biogeochemical modifications in ecosystem functioning. The Cuatro Cienegas Basin is an ancient oasis in the Mexican Chihuahuan desert that hosts a wide diversity of microbial mats and stromatolites that have survived in extremely oligotrophic pools with nearly constant conditions. However, thus far, the response of these unique microbial communities to long-term environmental disturbances remains unexplored. We therefore studied the compositional stability of these bacterial mat communities by using a replicated (3x) mesocosm experiment: a) Control; b) Fluct: fluctuating temperature; c) 40C: increase to 40 ºC; d) UVplus: artificial increase in UV radiation; and f) UVmin: UV radiation protection. In order to observe the changes in biodiversity, we obtained 16S rRNA gene clone libraries from microbial mats at the end of the experiment (eight months) and analyzed them using multivariate and phylogenetic tools. Sequences were assigned to 13 major lineages, among which Cyanobacteria (38.8%) and Alphaproteobacteria (25.5%) were the most abundant. The less extreme treatments (Control and UVmin) had a more similar composition and distribution of the phylogenetic groups with the natural pools than the most extreme treatments (Fluct, 40C, and UVplus), which showed drastic changes in the community composition and structure, indicating a different community response to each environmental disturbance. An increase in bacterial diversity was found in the UVmin treatment, suggesting that protected environments promote the establishment of complex bacterial communities, while stressful environments reduce diversity and increase the dominance of a few Cyanobacterial OTUs (mainly Leptolyngbya sp) through environmental filtering. Mesocosm experiments using complex bacterial communities, along with multivariate and phylogenetic analyses of molecular data, can

  9. Multivariate and phylogenetic analyses assessing the response of bacterial mat communities from an ancient oligotrophic aquatic ecosystem to different scenarios of long-term environmental disturbance.

    Directory of Open Access Journals (Sweden)

    Silvia Pajares

    Full Text Available Understanding the response of bacterial communities to environmental change is extremely important in predicting the effect of biogeochemical modifications in ecosystem functioning. The Cuatro Cienegas Basin is an ancient oasis in the Mexican Chihuahuan desert that hosts a wide diversity of microbial mats and stromatolites that have survived in extremely oligotrophic pools with nearly constant conditions. However, thus far, the response of these unique microbial communities to long-term environmental disturbances remains unexplored. We therefore studied the compositional stability of these bacterial mat communities by using a replicated (3x mesocosm experiment: a Control; b Fluct: fluctuating temperature; c 40C: increase to 40 ºC; d UVplus: artificial increase in UV radiation; and f UVmin: UV radiation protection. In order to observe the changes in biodiversity, we obtained 16S rRNA gene clone libraries from microbial mats at the end of the experiment (eight months and analyzed them using multivariate and phylogenetic tools. Sequences were assigned to 13 major lineages, among which Cyanobacteria (38.8% and Alphaproteobacteria (25.5% were the most abundant. The less extreme treatments (Control and UVmin had a more similar composition and distribution of the phylogenetic groups with the natural pools than the most extreme treatments (Fluct, 40C, and UVplus, which showed drastic changes in the community composition and structure, indicating a different community response to each environmental disturbance. An increase in bacterial diversity was found in the UVmin treatment, suggesting that protected environments promote the establishment of complex bacterial communities, while stressful environments reduce diversity and increase the dominance of a few Cyanobacterial OTUs (mainly Leptolyngbya sp through environmental filtering. Mesocosm experiments using complex bacterial communities, along with multivariate and phylogenetic analyses of molecular

  10. Evaluation of Function of Aquatic Ecosystem and Its Economic Value in Eighteen Creeks of Cangshan%苍山十八溪流域水资源生态系统服务功能价值评估

    Institute of Scientific and Technical Information of China (English)

    翟羽佳; 刘春学

    2015-01-01

    苍山十八溪是大理市主要饮用水源,也是洱海水补给的重要清洁水源地。为进一步认识水资源价值从而科学开发和利用水资源,提高节水意识,对苍山十八溪流域水资源生态系统服务功能进行了分类并分别对其进行价值评估。采用的评估方法有市场价值法、旅行费用法、机会费用法、影子工程法和影子价格,得到2013年十八溪流域水资源生态系统服务功能总价值为32.413亿元,包括经济服务功能23.17亿元和生态服务功能9.243亿元,其中,用水供应价值0.58亿元、水力发电价值0.12亿元、渔业生产价值1.83亿元、休闲娱乐价值20.64亿元,生态屏障价值7.122亿元、水质净化0.37亿元、调蓄水资源1.56亿元、生物多样性维持0.018亿元、降解污染物0.173亿元。从价值量来看,休闲娱乐价值和生态屏障价值所占比例较高,分别占总价值的63.7%和22%,可见十八溪对于大理市经济发展以及保护生态方面具有重要作用。%As the main resources of drinking water in Dali ,eighteen creeks of Cangshan is also an important major recharge resource of clean water to Erhai .In order to make further acquaintance with the value of water resources ,two kinds of aquatic ecosystem services are identified in this paper .Evaluating the value of the aquatic ecosystem services by market method ,travel expenses ,op‐portunity cost ,shadow project and shadow price which was 32 .263 billion RMB in 2013 ,the economic benefit value was 23 .02 bil‐lion RMB and the ecological function value was 9 .243 billion RMB .For the value of different functions ,water supply was 0 .58 bil‐lion RMB ,hydraulic electro-generating was 0 .12 billion RMB ,fishery industry was 1 .83 billion RMB ,entertainment was 20 .64 bil‐lion RMB ,ecological barrier was 7 .122 billion RMB ,water purification was 0 .37 billion RMB ,regulating water resources was 1 .56

  11. Ways forward for aquatic conservation: Applications of environmental psychology to support management objectives.

    Science.gov (United States)

    Walker-Springett, Kate; Jefferson, Rebecca; Böck, Kerstin; Breckwoldt, Annette; Comby, Emeline; Cottet, Marylise; Hübner, Gundula; Le Lay, Yves-François; Shaw, Sylvie; Wyles, Kayleigh

    2016-01-15

    The success or failure of environmental management goals can be partially attributed to the support for such goals from the public. Despite this, environmental management is still dominated by a natural science approach with little input from disciplines that are concerned with the relationship between humans and the natural environment such as environmental psychology. Within the marine and freshwater environments, this is particularly concerning given the cultural and aesthetic significance of these environments to the public, coupled with the services delivered by freshwater and marine ecosystems, and the vulnerability of aquatic ecosystems to human-driven environmental perturbations. This paper documents nine case studies which use environmental psychology methods to support a range of aquatic management goals. Examples include understanding the drivers of public attitudes towards ecologically important but uncharismatic river species, impacts of marine litter on human well-being, efficacy of small-scale governance of tropical marine fisheries and the role of media in shaping attitudes towards. These case studies illustrate how environmental psychology and natural sciences can be used together to apply an interdisciplinary approach to the management of aquatic environments. Such an approach that actively takes into account the range of issues surrounding aquatic environment management is more likely to result in successful outcomes, from both human and environmental perspectives. Furthermore, the results illustrate that better understanding the societal importance of aquatic ecosystems can reduce conflict between social needs and ecological objectives, and help improve the governance of aquatic ecosystems. Thus, this paper concludes that an effective relationship between academics and practitioners requires fully utilising the skills, knowledge and experience from both sectors.

  12. Six new Phytophthora species from ITS Clade 7a including two sexually functional heterothallic hybrid species detected in natural ecosystems in Taiwan.

    NARCIS (Netherlands)

    Jung, T.; Jung, M.H.; Scanu, B.; Seress, D.; Kovács, G.M.; Maia, C.; Pérez-Sierra, A.; Chang, T.-T.; Chandelier, A.; Heungens, K.; Poucke, van K.; Abad-Campos, P.; Léon, M.; Cacciola, S.O.; Bakonyi, J.

    2017-01-01

    During a survey of Phytophthora diversity in natural ecosystems in Taiwan six new species were detected. Multigene phylogeny based on the nuclear ITS, ß-tubulin and HSP90 and the mitochondrial cox1 and NADH1 gene sequences demonstrated that they belong to ITS Clade 7a with P. europaea, P. uniformis,

  13. Toxicological effects of pyrethroids on non-target aquatic insects.

    Science.gov (United States)

    Antwi, Frank B; Reddy, Gadi V P

    2015-11-01

    The toxicological effects of pyrethroids on non-target aquatic insects are mediated by several modes of entry of pyrethroids into aquatic ecosystems, as well as the toxicological characteristics of particular pyrethroids under field conditions. Toxicokinetics, movement across the integument of aquatic insects, and the toxicodynamics of pyrethroids are discussed, and their physiological, symptomatic and ecological effects evaluated. The relationship between pyrethroid toxicity and insecticide uptake is not fully defined. Based on laboratory and field data, it is likely that the susceptibility of aquatic insects (vector and non-vector) is related to biochemical and physiological constraints associated with life in aquatic ecosystems. Understanding factors that influence aquatic insects susceptibility to pyrethroids is critical for the effective and safe use of these compounds in areas adjacent to aquatic environments.

  14. A quantication of photoproduction of CO2 throughout the water column by degradation of terrigenous organic compounds present in the dissolved form for aquatic ecosystems of the boreal region in Quebec

    Science.gov (United States)

    Plouhinec, J.; Lucotte, M. M.; Ouellet, A.; Gelinas, Y.

    2010-12-01

    This study focuses on the quantity of CO2 produced by photodegradation in various pristine and disrupted water bodies. Photodegradation of dissolved organic matter (DOM) in the water column was evaluated in relation to two environmental factors e.g., the presence or absence of logging on the watershed and the contrast between natural lakes and hydroelectric reservoirs. Water samples were irradiated after filtration under 0,2µm, and subsequently analyzed for their CO2 production. Mean energy normalized for the spectral energy exposed to samples was determined to evaluate the photoreactivity of DOM under similar exposure conditions. In complement, organic matter samples had been concentrated via reverse osmosis. We then characterized the origin of DOM present in the water column with lignin biomarkers. Our results confirmed that the photomineralization increased significantly with DOM concentration. The daily photodegradation production was strikingly different in natural lakes and hydroelectric reservoirs. Average springtime and summertime production was evaluated at 5.45 ± 5.61 µmol.L-1.d-1 for lakes, compared to 14.21 ± 8.77 µmol.L-1.d-1 for boreal reservoirs. A similar comparison between ecosystems affected and unaffected by logging, also showed contrasting results for the photodegradation of DOM. Moreover, our lignin biomarkers increased significantly with CO2 generation. It thus appears that allochthonous organic matter strongly influences CO2 photoproduction. Finally, we evaluated the Photochemical Contribution to CO2 diffusive Fluxes (PCFCO2) between 14% and 32% depending on the degree of perturbation of the aquatic system.

  15. Caiman crocodilus yacare in Controlled Experiment: Statistical Confirmation of its Contribution to the Balance of Nutrients in an Aquatic Ecosystem of Mato-Grossense Pantanal, Brazil

    Directory of Open Access Journals (Sweden)

    Adelson Joel da Silva

    2010-04-01

    Full Text Available This study has like purpose to confirm, statistically, through controlled experiments the contribution of Caiman crocodilus yacare for the nutrient cycling of the lake Baía das pedras, Pantanal de Poconé - MT. Studies with this focus, beginnings only on 90’s endings, on the lake, during dry phase were counted about 1000 individuals of Caiman crocodilus yacare on only 20.800 m2. On this period the productivity of the lake is very high in relation to high water period, when the water became transparent, being that the Caymans develop on that time a very important role. It was used for the experiment a captivity of 8x6 m, with only one exit for water. In the center of the captivity there is a pool with 4x2 m width and 30 cm of depth. The animal was putted after the stabilization of the limnological variables inside of the pool. It were collected 6 samples of water, being three before and three after of the presence of the Cayman. The Cayman with 2,18 m size, with 57,8 kg was feed every day, Just after the limnologicals determinations, with fresh fish of specie Prochilodus lineatus (including visceral parts. It were realized total nitrogen and phosphorous analyzes, ammonium, nitrate, nitrite and orthophosphate of the water collected from the pool. It was verified the important role of Cayman crocodilus yacare in the experiment and in the region where it leaves.

  16. Aquatic Remediation of Communication Disorders.

    Science.gov (United States)

    Smith, Virginia M.

    1985-01-01

    A 10-day aquatics program for learning disabled children with hand-eye coordination problems and low self-esteem is described. Activities for each session (including relaxation exercises) are listed. (CL)

  17. Aquatic invasive species: Lessons from cancer research

    Science.gov (United States)

    Sepulveda, Adam; Ray, Andrew; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Gresswell, Robert E.; Gross, Jackson A.; Kershner, Jeffrey L.

    2014-01-01

    Aquatic invasive species are disrupting ecosystems with increasing frequency. Successful control of these invasions has been rare: Biologists and managers have few tools for fighting aquatic invaders. In contrast, the medical community has long worked to develop tools for preventing and fighting cancer. Its successes are marked by a coordinated research approach with multiple steps: prevention, early detection, diagnosis, treatment options and rehabilitation. The authors discuss how these steps can be applied to aquatic invasive species, such as the American bullfrog (Lithobates catesbeianus), in the Northern Rocky Mountain region of the United States, to expedite tool development and implementation along with achievement of biodiversity conservation goals.

  18. ZOONOSIS OF AQUATICAL ORGANISMS

    Directory of Open Access Journals (Sweden)

    Božidar Kurtović

    2001-12-01

    Full Text Available Aquatic organisms play a very important role in human nutrition. They also pose a real threat for human health by causing various diseases. Parasites, bacteria and viruses may either directly or indirectly be carried from aquatic organisms to humans. Disease outbreaks are influenced by many factors among which decreased immune response and feeding habits and higyene are most important. More frequent occuence of foodborne diseases has a number of reasons, including international travel and trade, microbial adaptation and changes in the food production system. Parasitic diseases occur most frequently as a result of human role in parasites life cycles. The prevalence is further increased by consuming raw fish and shellfish. The main feature of bacterial infections is facultative pathogenicity of most ethiological agents. In most cases disease occures as a result of decreased immunoreactivity. Several bacteria are, however, hightly pathogenic and capable of causing high morbidity and mortality in human. To date it has not been reported the case of human infection with viruses specific for aquatic organisms. Human infections are caused with human viruses and aquatic organisms play role only as vechicles. The greatest risk in that respect present shellfish. Fish and particularly shellfish are likely to cause food poisoning in humans. In most cases the cause are toxins of phithoplancton origins accumulating in shellfish and fish.

  19. Deer Island Aquatic Ecosystem Restoration Project

    Science.gov (United States)

    2015-07-01

    a profile conducive to small fish and avian foraging and reptile and mammal haul-out. This method, along with the soft-shore design (see below...Island, Biloxi, Mississippi. MS thesis, University of South Alabama . Mississippi Department of Marine Resources, Coastal Preserves Program Website

  20. Planning aquatic ecosystem restoration monitoring programs

    Energy Technology Data Exchange (ETDEWEB)

    Thom, R.M.; Wellman, K.F.

    1997-01-01

    This study was conducted as part of the Evaluation of Environmental Investments Research Program (EEIRP). The EEIRP is sponsored by the US Army Corps of Engineers. The objectives of this work are to (1) identify relevant approaches and features for environmental investment measures to be applied throughout the project life; (2) develop methods to access the effectiveness of the approach or feature for providing the intended environmental output; (3) develop and provide guidance for formulating environmental projects; and (4) provide guidance for formulating and identifying relevant cost components of alternate restoration plans.

  1. Nitrogen transformations in stratified aquatic microbial ecosystems

    DEFF Research Database (Denmark)

    Revsbech, Niels Peter; Risgaard-Petersen, N.; Schramm, Andreas;

    2006-01-01

    Abstract  New analytical methods such as advanced molecular techniques and microsensors have resulted in new insights about how nitrogen transformations in stratified microbial systems such as sediments and biofilms are regulated at a µm-mm scale. A large and ever-expanding knowledge base about n...

  2. Invasion and predation in aquatic ecosystems

    Institute of Scientific and Technical Information of China (English)

    Judith S. WEIS

    2011-01-01

    This article reviews biological invasions in which predation (or its absence) plays a major role in the success of the invader.Examples are described in which the invader out-competes native species for the same food,and cases in which the invader consumes valued native species.In many instances,better predator avoidance by the invasive species or the absence of predators in the new habitat contributes to the success of the invaders; in other cases native or introduced predators appear to be able to keep the invasive species in check.A relatively new management approach in the US is the idea of adding another trophic level-to have humans act as the predators and consume the invasive species.This approach is being utilized in Florida and throughout the Caribbean against the lionfish,but could be extended to other fishes,as well as to various invasive crustaceans and mollusks.This idea is controversial,and current regulations prohibiting the possession of individuals of the invasive species (e.g.,mitten crabs or snakefish) would preclude the development of a fishery for them [Current Zoology 57 (5):613-624,2011].

  3. A macrophyte submodel for aquatic ecosystems

    Science.gov (United States)

    Collins, Carol Desormeau; Wlosinski, Joseph H.

    1989-01-01

    A macrophyte submodel has been incorporated and tested in CE-QUAL-R1, a one-dimensional, vertically averaged model of reservoir water quality. A quasi two-dimensional scheme was necessary to represent the spatial relationship of macrophytes in reservoirs adequately. The macrophyte processes modeled were photosynthesis, dark respiration, excretion and nonpredatory mortality. Process equations for photosynthesis as a function of light and temperature, and dark respiration as a function of temperature were tested using data from laboratory studies. The submodel was field tested, along with other components of CE-QUAL-R1, using data collected at Eau Galle Reservoir, WI, U.S.A.

  4. 76 FR 60863 - Aquatic Nuisance Species Task Force Meeting

    Science.gov (United States)

    2011-09-30

    ... include: Commercial harvest of aquatic invasive species, State Aquatic Nuisance Species Management Plans...-Chair, Aquatic Nuisance Species Task Force, Acting Assistant Director--Fisheries and Habitat... Fish and Wildlife Service Aquatic Nuisance Species Task Force Meeting AGENCY: Fish and Wildlife...

  5. Biomarkers of toxicological responses in aquatic oligochaete, Lumbriculus. Variegatus

    Institute of Scientific and Technical Information of China (English)

    R. Gooneratne; Drewes C

    2005-01-01

    @@ Oligochaete worms are key, non-target,macroinvertebrates in terrestrial and freshwater ecosystems.Aquatic and terrestrial pollution has attracted a great deal of public interest in the past 2 decades.

  6. Insect herbivory on native and exotic aquatic plants: phosphorus and nitrogen drive insect growth and nutrient release

    NARCIS (Netherlands)

    Grutters, B.M.C.; Gross, E.M.; Bakker, E.S.

    2016-01-01

    Eutrophication and globalisation facilitate the dominance of exotic plants in aquatic ecosystems worldwide. Aquatic omnivores can provide biotic resistance to plant invasions, but little is known about whether obligate aquatic herbivores can do the same. Herbivores such as insects can decimate aquat

  7. Managed island ecosystems

    Science.gov (United States)

    McEachern, Kathryn; Atwater, Tanya; Collins, Paul W.; Faulkner, Kate R.; Richards, Daniel V.

    2016-01-01

    This long-anticipated reference and sourcebook for California’s remarkable ecological abundance provides an integrated assessment of each major ecosystem type—its distribution, structure, function, and management. A comprehensive synthesis of our knowledge about this biologically diverse state, Ecosystems of California covers the state from oceans to mountaintops using multiple lenses: past and present, flora and fauna, aquatic and terrestrial, natural and managed. Each chapter evaluates natural processes for a specific ecosystem, describes drivers of change, and discusses how that ecosystem may be altered in the future. This book also explores the drivers of California’s ecological patterns and the history of the state’s various ecosystems, outlining how the challenges of climate change and invasive species and opportunities for regulation and stewardship could potentially affect the state’s ecosystems. The text explicitly incorporates both human impacts and conservation and restoration efforts and shows how ecosystems support human well-being. Edited by two esteemed ecosystem ecologists and with overviews by leading experts on each ecosystem, this definitive work will be indispensable for natural resource management and conservation professionals as well as for undergraduate or graduate students of California’s environment and curious naturalists.

  8. AN ECOSYSTEM MODEL OF FISHERIES AND NUTRIENT ENRICHMENT

    DEFF Research Database (Denmark)

    Nguyen, Thanh Viet; Vestergaard, Niels

    2009-01-01

      Economic models of fishery largely ignore the linkages to lower trophic levels. In particular, environmental data and other bottom-up information is widely disregarded. Nor are changes in physical environment (bottom-up) alongside both exogenous and endogenous environmental effects included...... in the general ecosystem models. The objectives of this paper are modeling the impacts of nutrient enrichment on fisheries; particularly the impacts on consumer stocks and the fisheries based on these stocks are presented. We consider an aquatic ecosystem with four components: producers (autotrophs), consumers...

  9. The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems.

    Science.gov (United States)

    Young, Hillary S; McCauley, Douglas J; Dunbar, Robert B; Hutson, Michael S; Ter-Kuile, Ana Miller; Dirzo, Rodolfo

    2013-03-01

    Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.

  10. 水体生态系统对不同浓度水平苯酚污染的急性毒性响应%Response of aquatic ecosystem to phenol pollution at different concentration levels

    Institute of Scientific and Technical Information of China (English)

    张建英; 丁腾达; 梁璐怡; 王凤平; 陈瑾

    2012-01-01

    The effect of phenol on aquatic ecosystem was investigated by combining field monitoring and laboratory studies.Photobacterium phosphoreum,Scenedesmus quadricauda,Brachydanio rerio were selected in this study to explore the ecological response of producers,consumers and decomposers in the aquatic ecosystem to different concentrations of phenol stress.The results showed that toxic effects of phenol on luminescent bacteria,algae and fish were found,but there was no good linear relationship between inhibition rate of S.quadricauda and phenol concentration.Relationship of phenol concentration with the relative luminous efficiency of luminous bacteria indicated that the toxicity effect occurred at phenol concentrations higher than 0.2 mg·L-1.The toxic effect of phenol on S.quadricauda may be mainly due to the destruction of the dark reaction in photosynthesis.High concentration phenol promoted the growth,probably because phenol may be regarded as a carbon source for S.quadricauda.The weight loss,increased mortality,shortness of breath,swimming speed increase of zebra fish and deterioration of water quality were found after treatment of phenol concentration higher than 15 mg·L-1.The accumulated concentration of phenol in fish at 100 mg·L-1 exposure concentration was high,which could cause serious threat to human health through food chain.%针对浙江某地苯酚泄漏事件,结合实地监测和实验室研究,探索苯酚的水体污染化学行为对水体生态系统的影响和急性毒性效应.本研究选取水生生态系统中明亮发光杆菌T3、优势藻四尾栅藻Scenedesmus quadricauda以及模式鱼斑马鱼Brachydanio rerio为研究对象,探索水体中生产者、消费者及分解者等整个生态系统对不同苯酚浓度胁迫下的生态响应.结果表明,水生生物对苯酚污染浓度的生态响应差异显著,虽然苯酚对发光细菌、四尾栅藻及鱼体都具有一定的毒性影响,但四尾栅藻抑制率与苯酚浓度之

  11. Aquatic carbon fluxes from the conterminous US and Alaska

    Science.gov (United States)

    Butman, D. E.; Stackpoole, S. M.; Stets, E.; McDonald, C.; Clow, D. W.; Striegl, R. G.

    2015-12-01

    In 2007, the First State of the Carbon Cycle Report estimated that rivers exported ~ 35 Tg-C yr-1 to coastal systems and reservoirs in the US served as sink of ~ 25 Tg-C yr-1 through sedimentation, each reported with 95% confidence that the estimate was within 100%. Significant progress has been made to constrain and improve these estimates by carefully considering how inland water ecosystems dynamically process, transport, and sequester carbon with attention given to the gaseous evasion of carbon across the air-water interface, a component that was not included in the 2007 estimates. As part of the U.S. Geological Survey's LandCarbon program, we present the first integrated assessment of freshwater carbon cycling for the conterminous US and Alaska. We estimate that 147 (95% confidence interval of 101- 208) Tg-C yr-1 is exported downstream or emitted to the atmosphere and sedimentation stores 22 (95% confidence interval of 10-68) Tg-C yr-1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant removal flux at 85 Tg-C yr-1, or 58% of the total aquatic carbon flux. These new estimates for aquatic carbon fluxes indicate that inland waters must be considered in the context of national scale carbon accounting. For the conterminous US, we compare our results to the output of Terrestrial Biosphere Models. Analysis suggests that within the current modelling framework, calculations of Net Ecosystem Production may be overestimated by as much as 27%. Reconciliation of mass-flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional field data collection and modelling capacity.

  12. CEDEX research activities in Antarctica. Aquatic ecosystems in Byers Peninsula (Livingston Island, maritime Antarctica); Actividad investigadora del CEDEX en la Antartida. Ecosistemas acuaticos de la Peninsula Byers (Isla Livingston, Antartida)

    Energy Technology Data Exchange (ETDEWEB)

    Toro, M.; Quesada, A.; Camacho, A.; Oliva, M.; Alcami, A.; Antoniades, D.; Banon, M.; Fassnacht, S.; Fernandez-Valiente, E.; Galan, L.; Giralt, S.; Granados, I.; Justel, A.; Liu, E. J.; Lopez-Bravo, A.; Martinez-Cortizas, A.; Pla-Rabes, S.; Rastrojo, A.; Rico, E.; Rochera, C.; Van de Vijver, B.; Velazquez, D.; Villaescusa, J. A.; Vicent, W. F.

    2015-07-01

    Since 2001 CEDEX has taken part in many Antarctic joint research projects with different institutions from Spain and other countries, developing scientific activities in the International Camp of Byers Peninsular (Livingston Island, South Shetland Islands, Antarctica). This place was designed as an Antarctic Specially Protected Area (No.126) because the importance and value of its terrestrial and aquatic habitats. It is one of the largest ice-free areas of maritime Antarctica, with the highest diversity of environments and geological, hydrological and biological processes in the whole region, all of them in a pristine state. Byers Peninsula is considered the most significant limnological area in the Antarctic Peninsula region because it hosts a high number of lakes, ponds and streams, with an exceptional fauna and flora diversity, including the most singular, representative or endemic Antarctic species. Furthermore, the lakes sedimentary record is one of the widest and complete archives in Antarctic Peninsula region for the palaeocological and climatic study of the Holocene. Because Byers Peninsula is an Antarctic biodiversity hotspot, and it is located in one of the areas in the Earth where global warming is being more significant, it must be considered as a suitable international reference site for limnetic, terrestrial and coastal studies, and long term monitoring programmes. (Author)

  13. Thermal Pollution Impact upon Aquatic Life.

    Science.gov (United States)

    Shiomoto, Gail T.; Olson, Betty H.

    1978-01-01

    Conventional and nuclear power plants release waste heat to cooling water which then returns to receiving bodies of surface water. This thermal pollution causes a variety of effects in the aquatic ecosystem. More must be learned about these effects to ensure adequate regulation of thermal discharges. (RE)

  14. Acute Toxicity and Environmental Risks of Five Veterinary Pharmaceuticals for Aquatic Macroinvertebrates.

    Science.gov (United States)

    Bundschuh, Mirco; Hahn, Torsten; Ehrlich, Bert; Höltge, Sibylla; Kreuzig, Robert; Schulz, Ralf

    2016-02-01

    Due to the high use of antibiotics and antiparasitics for the treatment of livestock, there is concern about the potential impacts of the release of these compounds into freshwater ecosystems. In this context, the present study quantified the acute toxicity of two antibiotics (sulfadiazine and sulfadimidine), and three antiparasitic agents (flubendazole, fenbendazole, ivermectin) for nine freshwater invertebrate species. These experiments revealed a low degree of toxicity for the sulfonamide antibiotics, with limited implications in the survival of all test species at the highest test concentrations (50 and 100 mg/L). In contrast, all three antiparasitic agents indicated on the basis of their acute toxicity risks for the aquatic environment. Moreover, chronic toxicity data from the literature for antiparasitics, including effects on reproduction in daphnids, support the concern about the integrity of aquatic ecosystems posed by releases of these compounds. Thus, these pharmaceuticals warrant further careful consideration by environmental risk managers.

  15. A field guide to valuable underwater aquatic plants of the Great Lakes

    Science.gov (United States)

    Schloesser, Donald W.

    1986-01-01

    Underwater plants are a valuable part of the Great Lakes ecosystem, providing food and shelter for aquatic animals. Aquatic plants also help stabilize sediments, thereby reducing shoreline erosion. Annual fall die-offs of underwater plants provide food and shelter for overwintering small aquatic animals such as insects, snails, and freshwater shrimp.

  16. Nitrous oxide emission by aquatic macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Poulsen, Morten; Nielsen, Lars Peter

    2009-01-01

      A large variety of aquatic animals was found to emit the potent greenhouse gas nitrous oxide when nitrate was present in the environment. The emission was ascribed to denitrification by ingested bacteria in the anoxic animal gut, and the exceptionally high N2O-to-N2 production ratio suggested...... delayed induction of the last step of denitrification. Filter- and deposit-feeding animal species showed the highest rates of nitrous oxide emission and predators the lowest, probably reflecting the different amounts of denitrifying bacteria in the diet. We estimate that nitrous oxide emission by aquatic...... animals is quantitatively important in nitraterich aquatic environments like freshwater, coastal marine, and deep-sea ecosystems. The contribution of this source to overall nitrous oxide emission from aquatic environments might further increase because of the projected increase of nitrate availability...

  17. Accumulation and fluxes of mercury in terrestrial and aquatic food chains with special reference to Finland

    Directory of Open Access Journals (Sweden)

    Martin Lodenius

    2013-03-01

    Full Text Available Mercury is known for its biomagnification especially in aquatic food chains and for its toxic effects on different organisms including man. In Finland mercury has formerly been used in industry and agriculture and in addition many anthropogenic activities may increase the mercury levels in ecosystems. Phenyl mercury was widely used as slimicide in the pulp and paper industry in the 1950s and 1960s. In the chlor-alkali industry metallic mercury was used as catalyst at three plants. The most toxic form of mercury, methyl mercury, may be formed in soils, water, sediments and organisms. Many factors, including microbial activity, temperature, oxygen status etc., affect the methylation rate. In the lake ecosystem bioaccumulation of methyl mercury is very strong. In early 1980s there was a restriction of fishing concerning approximately 4000 km2 of lakes and sea areas because of mercury pollution. In aquatic systems we still find elevated concentrations near former emission sources. Long-range atmospheric transport and mechanical operations like ditching and water regulation may cause increased levels of mercury in the aquatic ecosystems. In the Finnish agriculture organic mercury compounds were used for seed dressing until 1992. Although the amounts used were substantial the concentrations in agricultural soils have remained rather low. In terrestrial food chains bioaccumulation is normally weak with low or moderate concentration at all ecosystem levels. Due to a weak uptake through roots terrestrial, vascular plants normally contain only small amounts of mercury. There is a bidirectional exchange of mercury between vegetation and atmosphere. Contrary to vascular plants, there is a very wide range of concentrations in fungi. Mercury may pose a threat to human health especially when accumulated in aquatic food chains.

  18. Sustainable exploitation and management of aquatic resources

    DEFF Research Database (Denmark)

    Neuenfeldt, Stefan; Köster, Fritz

    2014-01-01

    DTU Aqua conducts research, provides advice,educates at university level and contributes toinnovation in sustainable exploitation andmanagement of aquatic resources. The vision of DTUAqua is to enable ecologically and economicallysustainable exploitation of aquatic resourcesapplying an integrated...... management. Marineecosystems aims at understanding the mechanisms that govern the interaction between individuals,species and populations in an ecosystem enabling us to determine the stability and flexibility of theecosystem.Marine living resources looks at the sustainable utilization of fish and shellfish...... stocks.Ecosystem effects expands from the ecosystem approach to fisheries management to an integratedapproach where other human activities are taken into consideration. Fisheries management developsmethods, models and tools for predicting and evaluating the effects of management measures andregulations...

  19. A Study on Effect of Water Background on Canopy Spectral of Wetland Aquatic Plant.

    Science.gov (United States)

    Liu, Guang; Tang, Peng; Cai Zhan-qing; Wang, Tian-tian; Xu, Jun-feng

    2015-10-01

    Aquatic vegetation is the core of the wetland ecosystem, and it's also the main factor influencing the wetland ecosystem functions. In recent years, satellite remote sensing technology has been widely used in the investigation, classification and protection fields of wetland vegetation resources. Because of its unique growth environment, aquatic vegetation, the canopy spectrum of aquatic vegetation will be affected by water background elements including air-water interface, plankton in the water, sediment content, transparency, water depth, sediment, and the other optically active ingredients. When the remote sensing technology for wetland aquatic vegetation canopy spectral studies, should be considered the growth environment differences between aquatic and terrestrial vegetation. However, previous studies did not get the attention it deserves. This paper choose a typical water plant (Iris tentorium Maxim) as the research object, simulate the growth environment of wetland aquatic plants, use the feature spectrometer measurements the spectral reflectance of Iris tentorium Maxim vegetation canopy under different water depth gradient background (400-2 400 nm). Experimental results show that there is a significant negative correlation between background water depth and Iris canopy reflectance. Visible light band absolute correlation coefficient is above 0.9, near infrared band absolute correlation coefficient is above 0.8. In visible light and near infrared band, with water depth increases, the Iris canopy reflectance decreases obviously. Finally based on the highest correlation band of visible light and near infrared region (505, 717, 1 075 and 2 383 nm) established the linear equation between background water depth and the canopy reflectance, obtained the related parameters.

  20. Aquatic pollution increases use of terrestrial prey subsidies by stream fish

    Science.gov (United States)

    Kraus, Johanna M.; Pomeranz, Justin F.; Todd, Andrew S.; Walters, David M.; Schmidt, Travis S.; Wanty, Richard B.

    2016-01-01

    Stream food webs are connected with their riparian zones through cross-ecosystem movements of energy and nutrients. The use and impact of terrestrial subsidies on aquatic consumers is determined in part by in situ biomass of aquatic prey. Thus, stressors such as aquatic pollutants that greatly reduce aquatic secondary production could increase the need for and reliance of stream consumers on terrestrial resource subsidies.

  1. An integrated approach for assessing aquatic ecological carrying capacity: a case study of Wujin District in the Tai Lake Basin, China.

    Science.gov (United States)

    Zeng, Chen; Liu, Yaolin; Liu, Yanfang; Hu, Jiameng; Bai, Xiaogang; Yang, Xiaoyu

    2011-01-01

    Aquatic ecological carrying capacity is an effective method for analyzing sustainable development in regional water management. In this paper, an integrated approach is employed for assessing the aquatic ecological carrying capacity of Wujin District in the Tai Lake Basin, China. An indicator system is established considering social and economic development as well as ecological resilience perspectives. While calculating the ecological index, the normalized difference vegetation index (NDVI) is extracted from Moderate Resolution Imaging Spectroradiometer (MODIS) time-series images, followed by spatial and temporal analysis of vegetation cover. Finally, multi-index assessment of aquatic ecological carrying capacity is carried out for the period 2000 to 2008, including both static and dynamic variables. The results reveal that aquatic ecological carrying capacity presents a slight upward trend in the past decade and the intensity of human activities still exceeded the aquatic ecological carrying capacity in 2008. In terms of human activities, population has decreased, GDP has quadrupled, and fertilizer application and industrial wastewater discharge have declined greatly in the past decade. The indicators representing aquatic ecosystem conditions have the lowest scores, which are primarily attributed to the water eutrophication problem. Yet the terrestrial ecosystem is assessed to be in better condition since topographic backgrounds and landscape diversity are at higher levels. Based on the work carried out, it is suggested that pollutant emission be controlled to improve water quality and agricultural development around Ge Lake (the largest lake in Wujin District) be reduced.

  2. Functional feeding groups of aquatic insect families in Latin America: a critical analysis and review of existing literature.

    Science.gov (United States)

    Ramírez, Alonso; Gutiérrez-Fonseca, Pablo E

    2014-04-01

    Aquatic macroinvertebrates are involved in numerous processes within aquatic ecosystems. They often have important effects on ecosystem processes such as primary production (via grazing), detritus breakdown, and nutrient mineralization and downstream spiraling. The functional feeding groups (FFG) classification was developed as a tool to facilitate the incorporation of macroinvertebrates in studies of aquatic ecosystems. This classification has the advantage of combining morphological characteristics (e.g., mouth part specialization) and behavioral mechanisms (e.g., way of feeding) used by macroinvertebrates when consuming resources. Although recent efforts have greatly advanced our ability to identify aquatic macroinvertebrates, there is limited information on FFG assignment. Furthermore, there has been some variation in the use of the FFG classification, in part due to an emphasis on using gut content analysis to assign FFG, which is more appropriate for assigning trophic guilds. Thus, the main goals of this study are to (1) provide an overview of the value of using the FFG classification, (2) make an initial attempt to summarize available information on FFG for aquatic insects in Latin America, and (3) provide general guidelines on how to assign organisms to their FFGs. FFGs are intended to reflect the potential effects of organisms in their ecosystems and the way they consume resources. Groups include scrapers that consume resources that grow attached to the substrate by removing them with their mouth parts; shredders that cut or chew pieces of living or dead plant material, including all plant parts like leaves and wood; collectors-gatherers that use modified mouth parts to sieve or collect small particles (< 1 mm) accumulated on the stream bottom; filterers that have special adaptations to remove particles directly from the water column; and predators that consume other organisms using different strategies to capture them. In addition, we provide details on

  3. Aquatic Therapy for Children

    Science.gov (United States)

    Kucher, Greta; Moore, Kelsey; Rodia, Rachel; Moser, Christy Szczech

    2015-01-01

    Aquatic therapy has long been highlighted in the literature as a potentially powerful therapeutic intervention. This review will highlight basic definitions of aquatic therapy, review salient research, and identify specific diagnoses that may benefit from aquatic therapy. Online resources, blogs, and books that occupational therapists may find…

  4. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  5. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  6. Regime shifts, thresholds and multiple stable states in freshwater ecosystems; a critical appraisal of the evidence.

    Science.gov (United States)

    Capon, Samantha J; Lynch, A Jasmyn J; Bond, Nick; Chessman, Bruce C; Davis, Jenny; Davidson, Nick; Finlayson, Max; Gell, Peter A; Hohnberg, David; Humphrey, Chris; Kingsford, Richard T; Nielsen, Daryl; Thomson, James R; Ward, Keith; Mac Nally, Ralph

    2015-11-15

    The concepts of ecosystem regime shifts, thresholds and alternative or multiple stable states are used extensively in the ecological and environmental management literature. When applied to aquatic ecosystems, these terms are used inconsistently reflecting differing levels of supporting evidence among ecosystem types. Although many aquatic ecosystems around the world have become degraded, the magnitude and causes of changes, relative to the range of historical variability, are poorly known. A working group supported by the Australian Centre for Ecological Analysis and Synthesis (ACEAS) reviewed 135 papers on freshwater ecosystems to assess the evidence for pressure-induced non-linear changes in freshwater ecosystems; these papers used terms indicating sudden and non-linear change in their titles and key words, and so was a positively biased sample. We scrutinized papers for study context and methods, ecosystem characteristics and focus, types of pressures and ecological responses considered, and the type of change reported (i.e., gradual, non-linear, hysteretic or irreversible change). There was little empirical evidence for regime shifts and changes between multiple or alternative stable states in these studies although some shifts between turbid phytoplankton-dominated states and clear-water, macrophyte-dominated states were reported in shallow lakes in temperate climates. We found limited understanding of the subtleties of the relevant theoretical concepts and encountered few mechanistic studies that investigated or identified cause-and-effect relationships between ecological responses and nominal pressures. Our results mirror those of reviews for estuarine, nearshore and marine aquatic ecosystems, demonstrating that although the concepts of regime shifts and alternative stable states have become prominent in the scientific and management literature, their empirical underpinning is weak outside of a specific environmental setting. The application of these

  7. Research unit INTERNANO: Mobility, aging and functioning of engineered inorganic nanoparticles at the aquatic-terrestrial interface

    Science.gov (United States)

    Schaumann, Gabriele Ellen; Metreveli, George; Baumann, Thomas; Klitzke, Sondra; Lang, Friederike; Manz, Werner; Nießner, Reinhard; Schulz, Ralf; Vogel, Hans-Jörg

    2013-04-01

    Engineered inorganic nanoparticles (EINP) are expected to pass the wastewater-river-topsoil-groundwater pathway. Despite their increasing release, the processes governing the EINP aging and the changes in functionality in the environment are up to now largely unknown. The objective of the interdisciplinary research unit INTERNANO funded by the DFG is to identify the processes relevant for the fate of EINP and EINP-associated pollutants in the interfacial zone between aquatic and terrestrial ecosystems. The research unit consists of six subprojects and combines knowledge from aquatic and terrestrial sciences as well as from microbiology, ecotoxicology, physicochemistry, soil chemistry and soil physics. For the identification of key processes we will consider compartment specific flow conditions, physicochemistry and biological activity. Situations representative for a floodplain system are simulated using micromodels (μm scale) as well as incubation, soil column and joint laboratory stream microcosm experiments. These results will be transferred to a joint aquatic-terrestrial model system on EINP aging, transport and functioning across the aquatic-terrestrial transition zone. EINP isolation and characterization will be carried out via a combination of chromatographic, light scattering and microscopic methods including dynamic light scattering, elemental analysis, hydrodynamic radius chromatography, field flow fractionation as well as atomic force microscopy, Raman microscopy and electron microscopy. INTERNANO generates fundamental aquatic-terrestrial process knowledge, which will help to evaluate the environmental significance of the EINP at aquatic-terrestrial interfaces. Thus, INTERNANO provides a scientific basis to assess and predict the environmental impact of EINP release into the environment.

  8. Ecosystem vulnerability to climate change in the southeastern United States

    Science.gov (United States)

    Cartwright, Jennifer M.; Costanza, Jennifer

    2016-08-11

    Two recent investigations of climate-change vulnerability for 19 terrestrial, aquatic, riparian, and coastal ecosystems of the southeastern United States have identified a number of important considerations, including potential for changes in hydrology, disturbance regimes, and interspecies interactions. Complementary approaches using geospatial analysis and literature synthesis integrated information on ecosystem biogeography and biodiversity, climate projections, vegetation dynamics, soil and water characteristics, anthropogenic threats, conservation status, sea-level rise, and coastal flooding impacts. Across a diverse set of ecosystems—ranging in size from dozens of square meters to thousands of square kilometers—quantitative and qualitative assessments identified types of climate-change exposure, evaluated sensitivity, and explored potential adaptive capacity. These analyses highlighted key gaps in scientific understanding and suggested priorities for future research. Together, these studies help create a foundation for ecosystem-level analysis of climate-change vulnerability to support effective biodiversity conservation in the southeastern United States.

  9. Aquatic Exercise for the Aged.

    Science.gov (United States)

    Daniel, Michael; And Others

    The development and implementation of aquatic exercise programs for the aged are discussed in this paper. Program development includes a discussion of training principles, exercise leadership and the setting up of safe water exercise programs for the participants. The advantages of developing water exercise programs and not swimming programs are…

  10. Endocrine disruption in aquatic insects: a review.

    Science.gov (United States)

    Soin, Thomas; Smagghe, Guy

    2007-02-01

    There is mounting evidence that a wide variety of compounds can have endocrine disrupting effects on humans and wildlife. However, investigations so far have focused primarily on exposure to human and other vertebrates, with invertebrate findings largely restricted to marine mollusks or to the ecdysteroid and juvenile hormone agonists as purposely synthesized endocrine disrupters for the pest management of insects. This article provides a brief description of the insect hormone system, a short sum-up of the relevant insect groups with aquatic life stages, and an overview of the additional evidence for endocrine disruption in aquatic insects from laboratory and field studies since 1999. In addition, the suitability of insects as sentinels for endocrine disrupting chemicals in aquatic ecosystems is discussed. Conclusions are drawn and research needs are defined.

  11. Effects of invasive species on plant communities: an example using submersed aquatic plants at the regional level

    Science.gov (United States)

    Submerged aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects in the hydrological regime, sedimentation, nutrient cycling and habitats of associated fauna. Modifications of aquatic plant communities, as for example through the introduction of invasive s...

  12. Delineation of level III aquatic ecological function regionalization in the Taihu Lake basin%太湖流域水生态功能三级分区

    Institute of Scientific and Technical Information of China (English)

    高永年; 高俊峰; 陈垌烽; 许妍; 赵家虎

    2012-01-01

    Aquatic ecoregions have been used as spatial units for aquatic ecosystem management at the watershed scale. According to the protection requirements and characteristics of aquatic ecosystems in the Taihu Lake basin, the main purpose and the principles of level III aquatic ecological function regionalization delineation in this basin were proposed. Then the indicators for delineating level III aquatic ecological function regionalization were established based on regionalization objective and principles. The indicators for delineating level Ili aquatic ecological function regionalization in the non-Taihu Lake area included benthic Shannon-Wiener diversity index, chlorophyll content, water habitat types and benthic indicator species types (including Ephemera, Bivalvia, snail, Chironomidae and Oligochaeta), and the regionalization indicators for delineating level III aquatic ecological function regionalization in the Taihu Lake area included benthic Shannon-Wiener diversity index, chlorophyll content, water flow velocity and benthic indicator species (including Oligochaeta, Chironomidae class, Bivalvia, snail and others) ratio. With the aid of GIS technology, the spatial distribution of the indicators for level III aquatic ecological function regionalization delineation was identified based on the raster data from 1106 aquatic ecoregion function units in the non-Taihu Lake area and 3568 aquatic ecoregion function units in the Taihu Lake area, respectively. Two-step spatial clustering analysis approach and manual-assisted method were used to delineate level III aquatic ecological function zones. Then the Taihu Lake basin was divided into 21 level III aquatic ecological function zones. Moreover, the characteristics of the 21 zones were summarized, showing that there were significant differences in the aspects such as topography, soil type, water quality and aquatic ecology. The results of quantitative comparison of aquatic life also indicated that the benthic dominant

  13. AMEG: the new SETAC advisory group on aquatic macrophyte ecotoxicology

    OpenAIRE

    Arts, G.; Davies, J.; Dobbs, M.; Ebke, P.; Hanson, M; Hommen, U.; Knauer, K; Loutseti, S.; Maltby, L.; Mohr, S.; Poovey, A.; Poulsen, V.

    2010-01-01

    \\ud Introduction and background\\ud \\ud Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species be...

  14. Brominated flame retardant trends in aquatic birds from the Salish Sea region of the west coast of North America, including a mini-review of recent trends in marine and estuarine birds

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Aroha [Department of Applied Biology, University of British Columbia, 2357 Main Mall, Vancouver, BC (Canada); Elliott, John E., E-mail: John.Elliott@ec.gc.ca [Science and Technology, Environment Canada, Delta, BC V4K 3N2 (Canada); Elliott, Kyle H.; Guigueno, Mélanie F. [Department of Biology, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7 (Canada); Wilson, Laurie K. [Canadian Wildlife Service, Pacific Wildlife Research Centre, Environment Canada, Delta, BC V4K 3N2 (Canada); Lee, Sandi [Science and Technology, Environment Canada, Delta, BC V4K 3N2 (Canada); Idrissi, Abde [Environment Canada, National Wildlife Research Centre, Ottawa, ON K1A 0H3 (Canada)

    2015-01-01

    Polybrominated diphenyl ethers (PBDEs) increased in many matrices during the 1990s and early 2000s. Since voluntary restrictions and regulations on PBDEs were implemented in North America circa early 2000s, decreases in PBDEs have occurred in many of these same matrices. To examine temporal trends in the North Pacific, we retrospectively analysed PBDEs and eight non-PBDE flame retardants (FR) in eggs of two aquatic bird species, great blue herons, Ardea herodias, and double-crested cormorants, Phalacrocorax auritus, collected along the British Columbia coast, Canada from 1979 to 2012. Increasing PBDE concentrations were observed in both species followed by significant decreases post-2000 for all dominant congeners and ΣPBDE. Non-PBDE FRs were generally undetected in cormorant eggs, or detected at very low levels in heron eggs, except for hexabromocyclododecane (HBCDD). HBCDD, currently unregulated in North America, was not detected in early sampling years; however low concentrations were observed in both species in recent sampling years (2003–2012). Dietary tracers (δ{sup 13}C and δ{sup 15}N) did not change significantly over time, indicating that temporal changes in PBDEs are likely caused by implemented regulations. A comparison with recently published temporal trends of ΣPBDE in marine birds from North America and Europe is given. - Highlights: • Seabird eggs have been used to monitor POPs on the west coast of Canada since 1979. • Samples of these eggs were analysed retrospectively for PBDEs and HBCDD. • Regulations exist in North America to control PBDEs, but not HBCDD. • PBDEs decreased significantly since regulations were applied. • HBCDD was not detected pre-2003, but is now found in low concentrations.

  15. Consumer-driven nutrient dynamics in freshwater ecosystems: from individuals to ecosystems.

    Science.gov (United States)

    Atkinson, Carla L; Capps, Krista A; Rugenski, Amanda T; Vanni, Michael J

    2016-12-23

    The role of animals in modulating nutrient cycling [hereafter, consumer-driven nutrient dynamics (CND)] has been accepted as an important influence on both community structure and ecosystem function in aquatic systems. Yet there is great variability in the influence of CND across species and ecosystems, and the causes of this variation are not well understood. Here, we review and synthesize the mechanisms behind CND in fresh waters. We reviewed 131 articles on CND published between 1973 and 1 June 2015. The rate of new publications in CND has increased from 1.4 papers per year during 1973-2002 to 7.3 per year during 2003-2015. The majority of investigations are in North America with many concentrating on fish. More recent studies have focused on animal-mediated nutrient excretion rates relative to nutrient demand and indirect impacts (e.g. decomposition). We identified several mechanisms that influence CND across levels of biological organization. Factors affecting the stoichiometric plasticity of consumers, including body size, feeding history and ontogeny, play an important role in determining the impact of individual consumers on nutrient dynamics and underlie the stoichiometry of CND across time and space. The abiotic characteristics of an ecosystem affect the net impact of consumers on ecosystem processes by influencing consumer metabolic processes (e.g. consumption and excretion/egestion rates), non-CND supply of nutrients and ecosystem nutrient demand. Furthermore, the transformation and transport of elements by populations and communities of consumers also influences the flow of energy and nutrients across ecosystem boundaries. This review highlights that shifts in community composition or biomass of consumers and eco-evolutionary underpinnings can have strong effects on the functional role of consumers in ecosystem processes, yet these are relatively unexplored aspects of CND. Future research should evaluate the value of using species traits and abiotic

  16. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  17. Fish biodiversity sampling in stream ecosystems: a process for evaluating the appropriate types and amount of gear

    Science.gov (United States)

    Smith, Joseph M.; Wells, Sarah P.; Mather, Martha E.; Muth, Robert M.

    2014-01-01

    Because human impacts and climate change threaten aquatic ecosystems, a need exists to quantify catchment-scale biodiversity patterns and identify conservation actions that can mitigate adverse human impacts on aquatic biota.

  18. Ecotoxicological Assessment of Aquatic Genotoxicity Using the Comet Assay

    Directory of Open Access Journals (Sweden)

    KHUSNUL YAQIN

    2006-09-01

    Full Text Available Comet assay is a novel biological analysis, which is a sensitive, flexible, simple, rapid, and inexpensive method to assess aquatic genotoxicant. Since Singh and co-workers developed the method in 1988, its use has increased exponentially in various fields. This review discourses on the application of this assay in aquatic ecosystems. Various types of cells from various aquatic organisms have been tested by various genotoxicant both direct- and indirect-acting using the comet assay. The applications of this assay suggest that it is a useful assay to assess aquatic genotoxicants. However, there are some factors, which should be taken into account when using this assay as aquatic ecotoxicological assessment device such as inter-animal and cell variability.

  19. Characterization factors for thermal pollution in freshwater aquatic environments.

    Science.gov (United States)

    Verones, Francesca; Hanafiah, Marlia Mohd; Pfister, Stephan; Huijbregts, Mark A J; Pelletier, Gregory J; Koehler, Annette

    2010-12-15

    To date the impact of thermal emissions has not been addressed in life cycle assessment despite the narrow thermal tolerance of most aquatic species. A method to derive characterization factors for the impact of cooling water discharges on aquatic ecosystems was developed which uses space and time explicit integration of fate and effects of water temperature changes. The fate factor is calculated with a 1-dimensional steady-state model and reflects the residence time of heat emissions in the river. The effect factor specifies the loss of species diversity per unit of temperature increase and is based on a species sensitivity distribution of temperature tolerance intervals for various aquatic species. As an example, time explicit characterization factors were calculated for the cooling water discharge of a nuclear power plant in Switzerland, quantifying the impact on aquatic ecosystems of the rivers Aare and Rhine. The relative importance of the impact of these cooling water discharges was compared with other impacts in life cycle assessment. We found that thermal emissions are relevant for aquatic ecosystems compared to other stressors, such as chemicals and nutrients. For the case of nuclear electricity investigated, thermal emissions contribute between 3% and over 90% to Ecosystem Quality damage.

  20. Aquatic fungi: targeting the forgotten in microbial ecology.

    Science.gov (United States)

    Grossart, Hans-Peter; Rojas-Jimenez, Keilor

    2016-06-01

    Fungi constitute important and conspicuous components of aquatic microbial communities, but their diversity and functional roles remain poorly characterized. New methods and conceptual frameworks are required to accurately describe their ecological roles, involvement in global cycling processes, and utility for human activities, considering both cultivation-independent techniques as well as experiments in laboratory and in natural ecosystems. Here we highlight recent developments and extant knowledge gaps in aquatic mycology, and provide a conceptual model to expose the importance of fungi in aquatic food webs and related biogeochemical processes.

  1. Cetacean brains: how aquatic are they?

    Science.gov (United States)

    Marino, Lori

    2007-06-01

    The adaptation of cetaceans to a fully aquatic lifestyle represents one of the most dramatic transformations in mammalian evolutionary history. Two of the most salient features of modern cetaceans are their fully aquatic lifestyle and their large brains. This review article will offer an overview of comparative neuroanatomical research on aquatic mammals, including analyses of odontocete cetacean, sirenian, pinniped, and fossil archaeocete brains. In particular, the question of whether a relationship exists between being fully aquatic and having a large brain is addressed. It has been hypothesized that the large, well-developed cetacean brain is a direct product of adaptation to a fully aquatic lifestyle. The current consensus is that the paleontological evidence on brain size evolution in cetaceans is not consistent with this hypothesis. Cetacean brain enlargement took place millions of years after adaptation to a fully aquatic existence. Neuroanatomical comparisons with sirenians and pinnipeds provide no evidence for the idea that the odontocete's large brain, high encephalization level, and extreme neocortical gyrification is an adaptation to a fully aquatic lifestyle. Although echolocation has been suggested as a reason for the high encephalization level in odontocetes, it should be noted that not all aquatic mammals echolocate and echolocating terrestrial mammals (e.g., bats) are not particularly highly encephalized. Echolocation is not a requirement of a fully aquatic lifestyle and, thus, cannot be considered a sole effect of aquaticism on brain enlargement. These results indicate that the high encephalization level of odontocetes is likely related to their socially complex lifestyle patterns that transcend the influence of an aquatic environment.

  2. Long-term changes in pigmentation of arctic Daphnia provide potential for reconstructing aquatic UV exposure

    Science.gov (United States)

    Nevalainen, Liisa; Rantala, Marttiina V.; Luoto, Tomi P.; Ojala, Antti E. K.; Rautio, Milla

    2016-07-01

    Despite the biologically damaging impacts of solar ultraviolet radiation (UV) in nature, little is known about its natural variability, forcing mechanisms, and long-term effects on ecosystems and organisms. Arctic zooplankton, for example the aquatic keystone genus Daphnia (Crustacea, Cladocera) responds to biologically damaging UV by utilizing photoprotective strategies, including pigmentation. We examined the preservation and content of UV-screening pigments in fossil Daphnia remains (ephippia) in two arctic lake sediment cores from Cornwallis Island (Lake R1), Canada, and Spitsbergen (Lake Fugledammen), Svalbard. The aims were to document changes in the degree of UV-protective pigmentation throughout the past centuries, elucidate the adaptive responses of zooplankton to long-term variations in UV exposure, and estimate the potential of fossil zooplankton pigments in reconstructing aquatic UV regimes. The spectroscopic absorbance measurements of fossil Daphnia ephippia under UV (280-400 nm) and visible light (400-700 nm) spectral ranges indicated that melanin (absorbance maxima at UV wavebands 280-350 nm) and carotenoids (absorbance maxima at 400-450 nm) pigments were preserved in the ephippia in both sediment cores. Downcore measurements of the most important UV-protective pigment melanin (absorbance measured at 305 and 340 nm) showed marked long-term variations in the degree of melanisation. These variations likely represented long-term trends in aquatic UV exposure and were positively related with solar radiation intensity. The corresponding trends in melanisation and solar activity were disrupted at the turn of the 20th century in R1, but remained as strong in Fugledammen. The reversed trends in the R1 core were simultaneous with a significant aquatic community reorganization taking place in the lake, suggesting that recent environmental changes, likely related to climate warming had a local effect on pigmentation strategies. This time horizon is also

  3. Behavior and Potential Impacts of Metal-Based Engineered Nanoparticles in Aquatic Environments

    Directory of Open Access Journals (Sweden)

    Cheng Peng

    2017-01-01

    Full Text Available The specific properties of metal-based nanoparticles (NPs have not only led to rapidly increasing applications in various industrial and commercial products, but also caused environmental concerns due to the inevitable release of NPs and their unpredictable biological/ecological impacts. This review discusses the environmental behavior of metal-based NPs with an in-depth analysis of the mechanisms and kinetics. The focus is on knowledge gaps in the interaction of NPs with aquatic organisms, which can influence the fate, transport and toxicity of NPs in the aquatic environment. Aggregation transforms NPs into micrometer-sized clusters in the aqueous environment, whereas dissolution also alters the size distribution and surface reactivity of metal-based NPs. A unique toxicity mechanism of metal-based NPs is related to the generation of reactive oxygen species (ROS and the subsequent ROS-induced oxidative stress. Furthermore, aggregation, dissolution and ROS generation could influence each other and also be influenced by many factors, including the sizes, shapes and surface charge of NPs, as well as the pH, ionic strength, natural organic matter and experimental conditions. Bioaccumulation of NPs in single organism species, such as aquatic plants, zooplankton, fish and benthos, is summarized and compared. Moreover, the trophic transfer and/or biomagnification of metal-based NPs in an aquatic ecosystem are discussed. In addition, genetic effects could result from direct or indirect interactions between DNA and NPs. Finally, several challenges facing us are put forward in the review.

  4. Emergy and ecosystem complexity

    Science.gov (United States)

    Ulgiati, Sergio; Brown, Mark T.

    2009-01-01

    The question "What drives complexity?" is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles explain much of what is observed, including energy degradation according to the laws of thermodynamics. Emergy, a quantitative measure of the global environmental work supporting ecosystem dynamics, is used here in order to provide a deeper understanding of complexity growth and decline in ecosystems. Ecosystem complexity is discussed in this paper in relation to changes in structure, organization and functional capacity, as explained by changes in emergy, empower, and transformity.

  5. Ecosystem Jenga!

    Science.gov (United States)

    Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

    2009-01-01

    To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be…

  6. Natural ecosystems

    Science.gov (United States)

    Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan

    2013-01-01

    Natural Ecosystems analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern ecosystems and their species, portraying ecosystem disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.

  7. Comparison of leaf decomposition and macroinvertebrate colonization between exotic and native trees in a freshwater ecosystem

    NARCIS (Netherlands)

    Alonso, A.; Gonzalez-Munoz, N.; Castro-Diez, P.

    2010-01-01

    One of the most important sources of energy in aquatic ecosystems is the allochthonous input of detritus. Replacement of native tree species by exotic ones affects the quality of detritus entering freshwater ecosystems. This replacement can alter nutrient cycles and community structure in aquatic ec

  8. Using aquatic vegetation to remediate nitrate, ammonium, and soluble reactive phosphorus in simulated runoff

    Science.gov (United States)

    Within the agriculturally-intensive Mississippi River Basin of the United States, significant conservation efforts have focused on management practices that reduce nutrient runoff into receiving aquatic ecosystems. Only a small fraction of those efforts have focused on phytoremediation techniques. ...

  9. Public lakes, private lakeshore: modeling protection of native aquatic plants.

    Science.gov (United States)

    Schroeder, Susan A; Fulton, David C

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey (n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  10. Public Lakes, Private Lakeshore: Modeling Protection of Native Aquatic Plants

    Science.gov (United States)

    Schroeder, Susan A.; Fulton, David C.

    2013-07-01

    Protection of native aquatic plants is an important proenvironmental behavior, because plant loss coupled with nutrient loading can produce changes in lake ecosystems. Removal of aquatic plants by lakeshore property owners is a diffuse behavior that may lead to cumulative impacts on lake ecosystems. This class of behavior is challenging to manage because collective impacts are not obvious to the actors. This paper distinguishes positive and negative beliefs about aquatic plants, in models derived from norm activation theory (Schwartz, Adv Exp Soc Psychol 10:221-279, 1977) and the theory of reasoned action (Fishbein and Ajzen, Belief, attitude, intention, and behavior: an introduction to theory and research, Addison-Wesley, Boston 1975), to examine protection of native aquatic plants by Minnesota lakeshore property owners. We clarify how positive and negative evaluations of native aquatic plants affect protection or removal of these plants. Results are based on a mail survey ( n = 3,115). Results suggest that positive evaluations of aquatic plants (i.e., as valuable to lake ecology) may not connect with the global attitudes and behavioral intentions that direct plant protection or removal. Lakeshore property owners' behavior related to aquatic plants may be driven more by tangible personal benefits derived from accessible, carefully managed lakeshore than intentional action taken to sustain lake ecosystems. The limited connection of positive evaluations of aquatic plants to global attitudes and behavioral intentions may reflect either lack of knowledge of what actions are needed to protect lake health and/or unwillingness to lose perceived benefits derived from lakeshore property.

  11. Anatomical adaptations of aquatic mammals.

    Science.gov (United States)

    Reidenberg, Joy S

    2007-06-01

    This special issue of the Anatomical Record explores many of the anatomical adaptations exhibited by aquatic mammals that enable life in the water. Anatomical observations on a range of fossil and living marine and freshwater mammals are presented, including sirenians (manatees and dugongs), cetaceans (both baleen whales and toothed whales, including dolphins and porpoises), pinnipeds (seals, sea lions, and walruses), the sea otter, and the pygmy hippopotamus. A range of anatomical systems are covered in this issue, including the external form (integument, tail shape), nervous system (eye, ear, brain), musculoskeletal systems (cranium, mandible, hyoid, vertebral column, flipper/forelimb), digestive tract (teeth/tusks/baleen, tongue, stomach), and respiratory tract (larynx). Emphasis is placed on exploring anatomical function in the context of aquatic life. The following topics are addressed: evolution, sound production, sound reception, feeding, locomotion, buoyancy control, thermoregulation, cognition, and behavior. A variety of approaches and techniques are used to examine and characterize these adaptations, ranging from dissection, to histology, to electron microscopy, to two-dimensional (2D) and 3D computerized tomography, to experimental field tests of function. The articles in this issue are a blend of literature review and new, hypothesis-driven anatomical research, which highlight the special nature of anatomical form and function in aquatic mammals that enables their exquisite adaptation for life in such a challenging environment.

  12. Environmental analysis of endocrine disrupting effects from hydrocarbon contaminants in the ecosystem. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    McLachlan, J.

    1998-06-01

    'The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones (i.e., environmental hormones) in different species present in aquatic ecosystems. Species of particular focus are those which can serve as sentinel species (e.g., amphibians) and, thus, provide early warning signals for more widespread impacts on an ecosystem and its wildlife and human inhabitants. This reports the progress of 1.5 years of a three-year grant awarded to the Tulane/Xavier Center for Bioenvironmental Research (CBR). A growing body of evidence suggests that chemicals in the environment can disrupt the endocrine system of animals (i.e., wildlife and humans) and adversely impact the development of these species. Because of the multitude of known endocrine-disrupting chemicals and the numerous industrial and government sectors producing these chemicals, almost every federal agency has initiated research on the endocrine effects of chemicals relevant to their operations. This study represents the Department of Energy (DOE) Basic Energy Sciences'' only research on the impacts of endocrine-disrupting chemicals. The activities employed by this project to determine these impacts include development of biotechnology screens (in vitro), animal screens (in vivo), and other analyses of aquatic ecosystem biomarkers of exposure. The results from this study can elucidate how chemicals in the environment, including those from DOE activities, can signal (and alter) the development of a number of species in aquatic ecosystems. These signals can have detrimental impacts not only on an organismal level, but also on community, population, and entire ecosystem levels, including humans.'

  13. Sources, concentrations, and exposure effects of environmental gestagens on fish and other aquatic wildlife, with an emphasis on reproduction.

    Science.gov (United States)

    Orlando, Edward F; Ellestad, Laura E

    2014-07-01

    Fish and other aquatic wildlife, including frogs, turtles, and alligators, have been used as vertebrate sentinels for the effects of endocrine disrupting and other emerging chemicals of concern found in aquatic ecosystems. Research has focused on the effects of estrogenic, androgenic, and thyroidogenic compounds, but there is a growing body of literature on the reproductive health exposure effects of environmental gestagens on aquatic wildlife. Gestagens include native progestogens, such as progesterone, and synthetic progestins, such as gestodene and levonorgestrel, which bind progesterone receptors and have critically important roles in vertebrate physiology, especially reproduction. Roles for progestogen include regulating gamete maturation and orchestrating reproductive behavior, both as circulating hormones and as secreted pheromones. Gestagens enter the aquatic environment through paper mill effluent, wastewater treatment plant effluent, and agricultural runoff. A number of gestagens have been shown to negatively affect reproduction, development, and behavior of exposed fish and other aquatic wildlife at ng/L concentrations, and these compounds have been measured in the environment at single to 375 ng/L. Given the importance of endogenous progestogens in the regulation of gametogenesis, secondary sex characteristics, and reproductive behavior in vertebrates and the documented exposure effects of pharmaceutical progestins and progesterone, environmental gestagens are an emerging class of contaminants that deserve increased attention from researchers and regulators alike. The potential for environmental gestagens to affect the reproductive health of aquatic vertebrates seems evident, but there are a number of important questions for researchers to address in this nascent field. These include identifying biomarkers of gestagen exposure; testing the effects of environmentally relevant mixtures; and determining what other physiological endpoints and taxa might be

  14. 定量评估水生资源及生态系统的EWE营养模型研究%Study on EWE Nutrition Model for the Quantitative Assessment of Aquatic Resources and Ecosystem

    Institute of Scientific and Technical Information of China (English)

    欧阳力剑; 胥献宇; 胡思玉; 刘文

    2011-01-01

    According to environmental data. Ecopath with Ecosim (EWE) can quantitatively describe the energy flow in the produolion and consumption of function components of system by using trophodynamics, and accurately assess the biomass and stable state of aquatic ecosys tem. In the paper, the basic principle and parameter) of EWE model were introduced firstly, then the relationship between Q/B (the important parameter of EWE model) and basic life indies of fish was discussed, and the current study and typical results of EWE model were analyzed finally.%基于环境调查数据,EWE生态营养通道模型利用营养动力学原理,定量描述系统中各功能成分生产和消耗的能量流动,能较为准确地评估稳定状态下水域生态系统组份的生物量及其系统稳定状态:首先概括了EWE模型的基本原理和基本参数,然后探讨了EWE重要参数Q/B与鱼类基本生命指标之间的关系,最后分析了EWE模型的研究现状及典型研究成果.

  15. Richness and distribution of aquatic macrophytes in Brazilian semi-arid aquatic ecosystems Riqueza e distribuição de macrófitas aquáticas em ecossistemas aquáticos do semi-árido brasileiro

    Directory of Open Access Journals (Sweden)

    Gustavo Gonzaga Henry-Silva

    2010-06-01

    Full Text Available AIM: The aim of this study was to evaluate the richness and distribution of the aquatic macrophytes in the basin of the Apodi/Mossoró River, in the semi-arid region (caatinga of Rio Grande do Norte, Brazil; METHODS: A survey of the floristic composition of the aquatic macrophytes was made at 20 sampling stations in the basin at four seasons (August/2007, November/2007, February/2008, May/2008. Specimens of each species were collected and deposited in the Dárdano de Andrade Lima Herbarium of the Universidade Federal Rural do Semi-Árido; RESULTS: We found 40 species of aquatic macrophytes, in 33 genera and 22 families. The families with the most species were Poaceae and Cyperaceae, and the most species-rich genera were Cyperus and Eleocharis. The most common plant form was amphibian (42.5%, followed by emergent (27.5%, free-floating (12.5%, rooted-submersed (10.0%, and floating-leaved (7.5%. The lowest richness was observed at the estuarine region (3 species, and the highest richness in the upper basin (17 species. The rooted-submersed Hydrothrix gardneri Hooker f. and Ceratophyllum demersum L. were observed in great abundance and frequency in the Santa Cruz Reservoir of Apodi, especially in areas close to cage farms of Nile tilapia (Oreochromis niloticus (Linnaeus, 1758. The most common free-floating species were Eichhornia crassipes (Mart. Solms., Pistia stratiotes L., and Salvinia auriculata Aubl., predominantly in stretches that run through urban centers; CONCLUSION: The species richness of aquatic macrophytes in aquatic environments of the caatinga is similar to that observed in other basins of Brazil. Because of the many dams and reservoirs in the semi-arid Northeast, inventory and monitoring of aquatic macrophytes have become essential, especially in basins that will receive water from the diversion of the São Francisco River.OBJETIVO: Nós objetivamos avaliar a riqueza e a distribuição das macrófitas aquáticas nos ambientes aqu

  16. Semantic Support for Complex Ecosystem Research Environments

    Science.gov (United States)

    Klawonn, M.; McGuinness, D. L.; Pinheiro, P.; Santos, H. O.; Chastain, K.

    2015-12-01

    As ecosystems come under increasing stresses from diverse sources, there is growing interest in research efforts aimed at monitoring, modeling, and improving understanding of ecosystems and protection options. We aimed to provide a semantic infrastructure capable of representing data initially related to one large aquatic ecosystem research effort - the Jefferson project at Lake George. This effort includes significant historical observational data, extensive sensor-based monitoring data, experimental data, as well as model and simulation data covering topics including lake circulation, watershed runoff, lake biome food webs, etc. The initial measurement representation has been centered on monitoring data and related provenance. We developed a human-aware sensor network ontology (HASNetO) that leverages existing ontologies (PROV-O, OBOE, VSTO*) in support of measurement annotations. We explicitly support the human-aware aspects of human sensor deployment and collection activity to help capture key provenance that often is lacking. Our foundational ontology has since been generalized into a family of ontologies and used to create our human-aware data collection infrastructure that now supports the integration of measurement data along with simulation data. Interestingly, we have also utilized the same infrastructure to work with partners who have some more specific needs for specifying the environmental conditions where measurements occur, for example, knowing that an air temperature is not an external air temperature, but of the air temperature when windows are shut and curtains are open. We have also leveraged the same infrastructure to work with partners more interested in modeling smart cities with data feeds more related to people, mobility, environment, and living. We will introduce our human-aware data collection infrastructure, and demonstrate how it uses HASNetO and its supporting SOLR-based search platform to support data integration and semantic browsing

  17. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  18. Aquatic Life Benchmarks

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aquatic Life Benchmarks is an EPA-developed set of criteria for freshwater species. These benchmarks are based on toxicity values reviewed by EPA and used in the...

  19. Respiration in Aquatic Insects.

    Science.gov (United States)

    MacFarland, John

    1985-01-01

    This article: (1) explains the respiratory patterns of several freshwater insects; (2) describes the differences and mechanisms of spiracular cutaneous, and gill respiration; and (3) discusses behavioral aspects of selected aquatic insects. (ML)

  20. Carbon budget estimation of a subarctic catchment using a dynamic ecosystem model at high spatial resolution

    Science.gov (United States)

    Tang, J.; Miller, P. A.; Persson, A.; Olefeldt, D.; Pilesjo, P.; Heliasz, M.; Jackowicz-Korczynski, M.; Yang, Z.; Smith, B.; Callaghan, T. V.; Christensen, T. R.

    2015-05-01

    A large amount of organic carbon is stored in high-latitude soils. A substantial proportion of this carbon stock is vulnerable and may decompose rapidly due to temperature increases that are already greater than the global average. It is therefore crucial to quantify and understand carbon exchange between the atmosphere and subarctic/arctic ecosystems. In this paper, we combine an Arctic-enabled version of the process-based dynamic ecosystem model, LPJ-GUESS (version LPJG-WHyMe-TFM) with comprehensive observations of terrestrial and aquatic carbon fluxes to simulate long-term carbon exchange in a subarctic catchment at 50 m resolution. Integrating the observed carbon fluxes from aquatic systems with the modeled terrestrial carbon fluxes across the whole catchment, we estimate that the area is a carbon sink at present and will become an even stronger carbon sink by 2080, which is mainly a result of a projected densification of birch forest and its encroachment into tundra heath. However, the magnitudes of the modeled sinks are very dependent on future atmospheric CO2 concentrations. Furthermore, comparisons of global warming potentials between two simulations with and without CO2 increase since 1960 reveal that the increased methane emission from the peatland could double the warming effects of the whole catchment by 2080 in the absence of CO2 fertilization of the vegetation. This is the first process-based model study of the temporal evolution of a catchment-level carbon budget at high spatial resolution, including both terrestrial and aquatic carbon. Though this study also highlights some limitations in modeling subarctic ecosystem responses to climate change, such as aquatic system flux dynamics, nutrient limitation, herbivory and other disturbances, and peatland expansion, our study provides one process-based approach to resolve the complexity of carbon cycling in subarctic ecosystems while simultaneously pointing out the key model developments for capturing

  1. Roles of steady-state and dynamic models for regulation of hydrophobic chemicals in aquatic systems: A case study of decamethylcyclopentasiloxane (D5) and PCB-180 in three diverse ecosystems.

    Science.gov (United States)

    Kim, Jaeshin; Mackay, Donald; Powell, David E

    2017-02-12

    We seek to contribute to the improved regulatory use of mass balance models to complement environmental monitoring data by applying the steady-state Quantitative Water Air Sediment Interactive model (QWASI) and a novel unsteady-state QWASI model. A steady-state model can yield not only a useful simulation of chemical fate under near steady-state conditions, but it can provide insights into the likely influences of increasing or decreasing emission rates, temperature changes, and unexpectedly high sensitivities to model parameters that may require additional investigation. We compared the consistency of insights from both types of model, in the expectation that while the dynamic model provides a closer simulation of actual conditions, for many purposes a simple, less computationally demanding, more transparent and less expensive model may be adequate for many regulatory purposes. We investigated the response times of decamethylcyclopentasiloxane (D5) and PCB-180 concentrations in water and sediment under three emission scenarios in three different aquatic systems, namely Lake Ontario, Oslofjord, and Lake Pepin. D5 was predicted to be removed largely by hydrolysis and volatilization in Lake Ontario and Oslofjord whereas it is subject to removal by advective loss in Lake Pepin. The half-times of D5 water concentration to a stepwise reduction in emission were <60 days in all three water bodies. In contrast, the predicted half-times were 0.53, 1.4, and 2.9 years in Lake Pepin, Oslofjord, and Lake Ontario, respectively. We also explored how uncertainties in input parameters propagate into uncertainties of concentrations in water and sediments possibly necessitating more accurate values.

  2. Science to support aquatic animal health

    Science.gov (United States)

    Purcell, Maureen K.; Harris, M. Camille

    2016-10-18

    Healthy aquatic ecosystems are home to a diversity of plants, invertebrates, fish and wildlife. Aquatic animal populations face unprecedented threats to their health and survival from climate change, water shortages, habitat alteration, invasive species and environmental contaminants. These environmental stressors can directly impact the prevalence and severity of disease in aquatic populations. For example, periodic fish kills in the upper Chesapeake Bay Watershed are associated with many different opportunistic pathogens that proliferate in stressed fish populations. An estimated 80 percent of endangered juvenile Puget Sound steelhead trout die within two weeks of entering the marine environment, and a role for disease in these losses is being investigated. The introduction of viral hemorrhagic septicemia virus (VHSV) into the Great Lakes—a fishery worth an estimated 7 billion dollars annually—resulted in widespread fish die-offs and virus detections in 28 different fish species. Millions of dying sea stars along the west coast of North America have led to investigations into sea star wasting disease. U.S. Geological Survey (USGS) scientists are assisting managers with these issues through ecological investigations of aquatic animal diseases, field surveillance, and research to promote the development of mitigation strategies.

  3. Aquatic risk assessment of pesticides in Latin America

    NARCIS (Netherlands)

    Carriquiriborde, P.; Mirabella, P.; Waichman, A.; Solomon, K.; Brink, van den P.J.; Maund, S.J.

    2014-01-01

    Latin America is anticipated to be a major growth market for agriculture and production is increasing with use of technologies such as pesticides. Reports of contamination of aquatic ecosystems by pesticides in Latin America have raised concerns about potential for adverse ecological effects. In the

  4. Modelling bioaccumulation of oil constituents in aquatic species

    NARCIS (Netherlands)

    Hoop, de L.; Huijbregts, M.A.J.; Schipper, A.M.; Veltman, K.; Laender, de F.; Viaene, K.P.J.; Klok, C.; Hendriks, A.J.

    2013-01-01

    Crude oil poses a risk to marine ecosystems due to its toxicity and tendency to accumulate in biota. The present study evaluated the applicability of the OMEGA model for estimating oil accumulation in aquatic species by comparing model predictions of kinetic rates (absorption and elimination) and bi

  5. Total Ecosystem Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Total ecosystem carbon includes above- and below-ground live plant components (such as leaf, branch, stem and root), dead biomass (such as standing dead wood, down...

  6. Evaluating the Impact of Land Use Change on Submerged Aquatic Vegetation Stressors in Mobile Bay

    Science.gov (United States)

    Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Quattrochi, Dale; Thom, Ronald; Woodruff, Dana; Judd, Chaeli; Ellis, Jean; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

    2009-01-01

    Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land use change in Mobile and Baldwin counties on SAV stressors and controlling factors (temperature, salinity, and sediment) in Mobile Bay. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for land use scenarios in 1948, 1992, 2001, and 2030. Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 land use scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the Bay. Theses results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid with four vertical profiles throughout Mobile Bay. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to land use driven flow changes with the restoration potential of SAVs.

  7. Aquatic Plant Control Research Program. Allelopathic Aquatic Plants for Aquatic Plant Management: A Feasibility Study

    Science.gov (United States)

    1989-10-01

    block number) FIELD GROUP SUB-GROUP Allelopathy "Bioassay . Growth inhibition. Aquatic macrophytes. Biocontrol Lena minor 19. ABSTRACT (Continue on...Bibliography of Aquatic Plant Allelopathy ........ Al 2 ALLELOPATHIC AQUATIC PLANTS FOR AQUATIC PLANT MANAGEMENT; A FEASIBILITY STUDY Introduction Background 1...nutrients, water, and other biotic effects could have overriding effects that appear as competition or allelopathy . These biotic factors must be

  8. HAZARDOUS MATERIALS IN AQUATIC ENVIRONMENTS OF THE MISSISSIPPI RIVER BASIN

    Energy Technology Data Exchange (ETDEWEB)

    John A. McLachlan

    2003-12-01

    to understanding how heavy metals move through wetlands environments. These data, coupled with plume characterization data, indicate that Bayou Trepagnier is a model system for understanding how wetlands populations of fish, amphibians, and plants respond to long-term hydrocarbon and metals contamination. The CBR has fifteen years of experience in developing model aquatic ecosystems for evaluating environmental problems relevant to DOE cleanup activities. Using biotechnology screens and biomarkers of exposure, this project supports other CBR research demonstrating that chemicals in the environment can signal/alter the development of species in aquatic ecosystems, and show detrimental impacts on community, population, and the ecosystem, including human health. CBR studies funded through this grant have resulted in private sector investments, international collaborations, development of new technologies, and substantial new knowledge concerning the effects of hazardous materials on human and ecosystem health. Through the CBR, Tulane and Xavier Universities partnered with DOE-EM to lay groundwork for an effective research agenda that has become part of the DOE long term stewardship science and technology program and institutional management of the DOE complex.

  9. Toxicity of trifluoroacetate to aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Berends, A.G.; Rooij, C.G. de [Solvay S.A., Brussels (Belgium); Boutonnet, J.C. [Elf Atochem, Levallois-Perret (France); Thompson, R.S. [Zeneca Ltd., Devon (United Kingdom). Brixham Environmental Lab.

    1999-05-01

    As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio retrio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba Ge) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, they determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Eugelan gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, they can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

  10. [Urban ecosystem services: A review].

    Science.gov (United States)

    Mao, Qi-zheng; Huang, Gan-lin; Wu, Jian-guo

    2015-04-01

    Maintaining and improving ecosystem services in urban areas and human well-being are essential for sustainable development and therefore constitute an important topic in urban ecology. Here we reviewed studies on ecosystem services in urban areas. Based on the concept and classification of urban ecosystem services, we summarized characteristics of urban ecosystem services, including the human domination, high demand of ecosystem services in urban areas, spatial heterogeneity and temporal dynamics of ecosystem services supply and demand in urban areas, multi-services of urban green infrastructures, the socio-economic dimension of ecosystem services supply and ecosystem disservices in urban areas. Among different urban ecosystem services, the regulating service and cultural service are particularly indispensable to benefit human health. We pointed out that tradeoffs among different types of ecosystem services mostly occur between supportive service and cultural service, as well as regulating service and cultural service. In particular, we emphasized the relationship between landscape design (i.e. green infrastructure) and ecosystem services supply. Finally, we discussed current gaps to link urban ecosystem services studies to landscape design and management and pointed out several directions for future research in urban ecosystem services.

  11. Monitoring aquatic environments with autonomous systems

    DEFF Research Database (Denmark)

    Christensen, Jesper Philip Aagaard

    High frequency measurements from autonomous sensors have become a widely used tool among aquatic scientists. This report focus primarily on the use of ecosystem metabolism based on high frequency oxygen measurements and relates the calculations to spatial variation, biomass of the primary producers...... and in shallow systems the macrophytes can completely dominate primary production. This was despite the fact that the plants in the studied system were light-saturated most of the light hours and occasionally carbon limited. It was also shown that the GPP and the total phytoplankton biomass in a nutrient...

  12. Water environments: anthropogenic pressures and ecosystem changes in the Atlantic drainage basins of Brazil.

    Science.gov (United States)

    Marques, Marcia; da Costa, Monica F; Mayorga, Maria Irles de O; Pinheiro, Patrícia R

    2004-02-01

    Densely occupied drainage basins and coastal zones in developing countries that are facing economic growth are likely to suffer from moderate to severe environmental impacts regarding different issues. The catchment basins draining towards the Atlantic coast from northeastern to southern Brazil include a wide range of climatic zones and diverse ecosystems. Within its borders lies the Atlantic rain forest, significant extensions of semiarid thorn forests (caatinga), vast tree and scrub woodlands (cerrado) and most of the 6670 km of the Brazilian coast and its marine ecosystems. In recent decades, human activities have increasingly advanced over these natural resources. Littoralization has imposed a burden on coastal habitats and communities. Most of the native vegetation of the cerrado and caatinga was removed and only 7% of the original Atlantic rainforest still exists. Estuaries, bays and coastal lagoons have been irreversibly damaged. Land uses, damming and water diversion have become the major driving forces for habitat loss and aquatic ecosystem modification. Regardless of the contrast between the drought-affected northeastern Brazil and the much more prosperous and industrialized southeastern/southern Brazil, the impacts on habitat and communities were found equally severe in both cases. Attempts to halt environmental degradation have not been effective. Instead of focusing on natural resources separately, it is suggested that more integrated environmental policies that focus on aquatic ecosystems integrity are introduced.

  13. Aquatic Plant Control Research Program: Effects of Water Chemistry on Submersed Aquatic Plants: A Synthesis

    Science.gov (United States)

    1990-07-01

    plants exhibiting C4 photosynthesis, C is conserved by refixing photorespired CO2. These terres- trial adaptations have counterparts in the aquatic...such as low photorespiration rates and low CO2 compensation points. The advantages of this photosynthetic pathway include conservation of... photorespired C and efficient C assimilation under the high dissolved oxygen and low free CO2 concentrations common in dense submersed aquatic plant populations

  14. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der

    This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

  15. Quantum and Ecosystem Entropies

    Directory of Open Access Journals (Sweden)

    A. D. Kirwan

    2008-06-01

    Full Text Available Ecosystems and quantum gases share a number of superficial similarities including enormous numbers of interacting elements and the fundamental role of energy in such interactions. A theory for the synthesis of data and prediction of new phenomena is well established in quantum statistical mechanics. The premise of this paper is that the reason a comparable unifying theory has not emerged in ecology is that a proper role for entropy has yet to be assigned. To this end, a phase space entropy model of ecosystems is developed. Specification of an ecosystem phase space cell size based on microbial mass, length, and time scales gives an ecosystem uncertainty parameter only about three orders of magnitude larger than Planck’s constant. Ecosystem equilibria is specified by conservation of biomass and total metabolic energy, along with the principle of maximum entropy at equilibria. Both Bose - Einstein and Fermi - Dirac equilibrium conditions arise in ecosystems applications. The paper concludes with a discussion of some broader aspects of an ecosystem phase space.

  16. Act together – implications of symbioses in aquatic ciliates

    Directory of Open Access Journals (Sweden)

    Claudia eDziallas

    2012-08-01

    Full Text Available Mutual interactions in form of symbioses can increase the fitness of organisms and provide them with the capacity to occupy new ecological niches. The formation of obligate symbioses allows for rapid evolution of new life forms including multitrophic consortia. Microbes are important components of many known endosymbioses and their short generation times and strong potential for genetic exchange may be important drivers of speciation. Hosts provide endo- and ectosymbionts with stable, nutrient-rich environments and protection from environmental stresses. This is of particular importance in aquatic ecosystems, which are often highly variable, harsh and nutrient-deficient habitats. Thus it is not surprising that symbioses are widespread in both marine and freshwater environments. Symbioses in aquatic ciliates are good model systems for exploring symbiont-host interactions. Many ciliate species are globally distributed and have been intensively studied in the context of plastid evolution. Their relatively large cell size offers an ideal habitat for numerous microorganisms with different functional traits including commensalism and parasitism. Phagocytosis facilitates the formation of symbiotic relationships, particularly since some ingested microorganisms can escape the digestion. For example, photoautotrophic algae and methanogens represent endosymbionts that greatly extend the biogeochemical functions of their hosts. Consequently, symbiotic relationships between protists and prokaryotes are widespread and often result in new ecological functions of symbiotic communities. This enables ciliates to thrive under a wide range of environmental conditions including ultraoligotrophic or anoxic habitats. We summarize the current understanding of this exciting research topic to identify the many areas in which knowledge is lacking and to stimulate future research by providing an overview on new methodologies and by formulating a number of emerging

  17. Carbon budget estimation of a subarctic catchment using a dynamic ecosystem model at high spatial resolution

    Directory of Open Access Journals (Sweden)

    J. Tang

    2015-01-01

    Eriophorum, Sphagnum and then tundra heath during the observation periods. The catchment-level carbon fluxes from aquatic systems are dominated by CO2 emissions from streams. Integrated across the whole catchment, we estimate that the area is a carbon sink at present, and will become an even stronger carbon sink by 2080, which is mainly a result of a projected densification of birch forest and its encroachment into tundra heath. However, the magnitudes of the modelled sinks are very dependent on future atmospheric CO2 concentrations. Furthermore, comparisons of global warming potentials between two simulations with and without CO2 increase since 1960 reveal that the increased methane emission from the peatland could double the warming effects of the whole catchment by 2080 in the absence of CO2 fertilization of the vegetation. This is the first process-based model study of the temporal evolution of a catchment-level carbon budget at high spatial resolution, integrating comprehensive and diverse fluxes including both terrestrial and aquatic carbon. Though this study also highlights some limitations in modelling subarctic ecosystem responses to climate change including aquatic system flux dynamics, nutrient limitation, herbivory and other disturbances and peatland expansion, our application provides a mechanism to resolve the complexity of carbon cycling in subarctic ecosystems while simultaneously pointing out the key model developments for capturing complex subarctic processes.

  18. Aquatic Environment 2000

    DEFF Research Database (Denmark)

    Svendsen, L. M.; Bijl, L. van der; Boutrup, S.

    The report summarizes the results of the Danish Aquatic Monitoring and Assessment Programme 1998-2003. Danish Environmental Protection Agency 2000: NOVA-2003. Programbeskrivelse for det nationale program for overvågning af vandmiljøet 1998-2003. 397 pp. - Redegørelse fra Miljøstyrelsen nr. 1 (in...

  19. Aquatic Equipment Information.

    Science.gov (United States)

    Sova, Ruth

    Equipment usually used in water exercise programs is designed for variety, intensity, and program necessity. This guide discusses aquatic equipment under the following headings: (1) equipment design; (2) equipment principles; (3) precautions and contraindications; (4) population contraindications; and (5) choosing equipment. Equipment is used…

  20. Potential of some aquatic plants for removal of arsenic from wastewater by green technology

    Directory of Open Access Journals (Sweden)

    Mohammed Barznji Dana A.

    2015-03-01

    Full Text Available Phytoremediation or green technology is counted among the successful and effective biological contaminated water treatment techniques. Basically, the concept of this green, cost-effective, simple, environmentally nondisruptive method consists in using plants and microbiological processes to reduce contaminants in the ecosystem. Different species from aquatic plants (emerged, free-floating, and submerged have been studied to mitigate toxic contaminants such as arsenic, cadmium, chromium, copper, lead, mercury, zinc, etc. Arsenic is one of the most severe toxic elements; it is widely distributed in the environment, usually found in combination with chloride, oxygen, sulphur and metal ions as a result of mineral dissolution from sedimentary or volcanic rocks and the dilution of geothermal water. The effluents from both industrial and agricultural sectors are also regarded as sources to contaminate water. From the accumulation point of view, several aquatic plants have been mentioned as good arsenic accumulators and their performance is evaluated using the green technology method. These include Spirodela polyrhiza, Wolffia globosa, Lemna gibba, L. minor, Eichhornia crassipes, Azolla caroliniana, Azolla filiculoides, Azolla pinnata, Ceratophyllum demersum and Pistia stratiotes. The up-to-date information illustrated in this review paper generates knowledge about the ability of some common aquatic plants around the globe to remediate arsenic from contaminated water.

  1. Aquatic Plants and their Control.

    Science.gov (United States)

    Michigan State Dept. of Natural Resources, Lansing.

    Aquatic plants can be divided into two types: algae and macrophytes. The goal of aquatic plant management is to maintain a proper balance of plants within a lake and still retain the lake's recreational and economic importance. Aquatic plant management programs have two phases: long-term management (nutrient control), and short-term management…

  2. Diversity of phytoplankton community in different urban aquatic ecosystems in metropolitan João Pessoa, state of Paraíba, Brazil Diversidade da comunidade fitoplactônica em diferentes ecossistemas aquáticos urbanos da região metropolitana de João Pessoa, PB, estado da Paraíba, Brasil

    Directory of Open Access Journals (Sweden)

    Davi Freire da Costa

    2011-12-01

    Full Text Available AIM: The aim of the present study was to identify which environmental factors affect the seasonal phytoplankton structure in different types of tropical aquatic ecosystems. Phytoplankton sampling was performed bi-monthly from August 2009 to June 2110 at three sites in the Solon de Lucena Lake, Jaguaribe River and Águas Minerais reservoir. METHODS: The environmental variables were water temperature, transparency, depth, degree of infestation of aquatic macrophytes, air temperature, wind speed, solar radiation and precipitation. The phytoplankton community was studied in terms of richness, density, diversity and evenness. The data were treated with analysis of variance and canonical correspondence analysis. RESULTS: Spatial variations in the data only occurred between ecosystems (p OBJETIVO: Este trabalho visou identificar que fatores ambientais interferem na estrutura sazonal fitoplanctônica em diferentes tipos de ecossistemas aquáticos tropicais. Coletas do fitoplâncton foram realizadas bimestralmente de agosto/2009 até junho/2010 em três pontos na lagoa Solon de Lucena, no rio Jaguaribe e no reservatório das Águas Minerais. MÉTODOS: As variáveis ambientais utilizadas neste estudo foram temperatura e transparência da água, profundidade, níveis de infestação de macrófitas aquáticas, temperatura do ar, velocidade do vento, radiação solar e precipitação pluviométrica. A comunidade fitoplanctônica foi estudada em nível de riqueza, densidade, diversidade e equitatividade. Os dados foram tratados através de análise de variância e ACC. RESULTADOS: A variação espacial dos dados foi observada apenas entre os ecossistemas (p < 0,05. O reservatório e o rio apresentaram fitoplâncton típico de ambientes lóticos com maior riqueza de Bacillariophyta (52,8% e 47,8%, respectivamente. Entretanto, a lagoa apresentou riqueza típica de ambientes lacustres com maior contribuição de Chlorophyta (52,8%. Este ecossistema diferente dos

  3. Aquatic animal telemetry: A panoramic window into the underwater world

    DEFF Research Database (Denmark)

    Hussey, Nigel E.; Kessel, Steven T.; Aarestrup, Kim;

    2015-01-01

    providing unprecedented ecological insights by connecting animal movements with measures of their physiology and environment. These developments are revolutionizing the scope and scale of questions that can be asked about the causes and consequences of movement and are redefining how we view and manage......The distribution and interactions of aquatic organisms across space and time structure our marine, freshwater, and estuarine ecosystems. Over the past decade, technological advances in telemetry have transformed our ability to observe aquatic animal behavior and movement. These advances are now...

  4. Liver histopathology of the sharptooth catfish Clarias gariepinus as a biomarker of aquatic pollution.

    Science.gov (United States)

    van Dyk, J C; Cochrane, M J; Wagenaar, G M

    2012-04-01

    This paper reports on a comparative perspective of liver histopathological data of the sharptooth catfish Clarias gariepinus. The data was collected from a spectrum of relatively un-impacted and isolated, to polluted, eutrophic freshwater ecosystems. Results were compared between regional areas, by combining data from freshwater systems which has a similar pollution status and/or is located within the same geographical region. Measurements included necropsy observations, semi-quantitative liver histopathology (Liver Index), and selected biometrical indices. The aim was to establish whether the results of these measurements would differ between, and/or reflect the pollution status of, the different freshwater aquatic ecosystems. The histopathological analysis showed a higher prevalence of toxicopathic non-neoplastic, and pre-neoplastic alterations in C. gariepinus from the polluted sites. We also found a significant difference between the Liver Index, hepatosomatic index, and condition factor values of fish inhabiting impoundments known to be polluted, compared to the same species from the selected reference sites. Fish from polluted sites also had more macroscopic liver abnormalities. The results suggest that the liver histopathology of this bio-indicator fish species could be a useful biomarker of freshwater aquatic pollution.

  5. Effects of triclosan on various aquatic organisms.

    Science.gov (United States)

    Tatarazako, Norihisa; Ishibashi, Hiroshi; Teshima, Kenji; Kishi, Katsuyuki; Arizono, Koji

    2004-01-01

    Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) is widely used as an antibacterial agent in various industrial products, such as textile goods, soap, shampoo, liquid toothpaste and cosmetics, and often detected in wastewater effluent. However, there is a paucity of data on the toxicity of triclosan and its effects on aquatic organisms. In this study, the acute toxicity of triclosan to the Microtox bacterium (Vibrio fischeri), a microalga (Selenastrum capricornutum), a crustacean (Ceriodaphnia dubia) and fish (Danio rerio and Oryzias latipes) was examined. As a result, the MicrotoxR bacterium, crustacean and fish had similar sensitivities towards triclosan toxicity (i.e., IC25 from 0.07 to 0.29 mg/L triclosan). In contrast, the microalga was about 30-80-fold (IC25 = 0.0034 mg/L triclosan) more sensitive to triclosan toxicity than the bacterium and fish. Therefore, triclosan is quite highly toxic to aquatic animals, and is particularly highly toxic to the green alga used as a test organism in this study. This result indicates that triclosan exerts a marked influence on algae, which are important organisms being the first-step producers in the ecosystem; therefore, the possible destruction of the balance of the ecosystem is expected if triclosan is discharged into the environment at high levels.

  6. The NEON Aquatic Network: Expanding the Availability of Biogeochemical Data

    Science.gov (United States)

    Vance, J. M.; Bohall, C.; Fitzgerald, M.; Utz, R.; Parker, S. M.; Roehm, C. L.; Goodman, K. J.; McLaughlin, B.

    2013-12-01

    Aquatic ecosystems are facing unprecedented pressure from climate change and land-use practices. Invasive species, whether plant, animal, insect or microbe present additional threat to aquatic ecosystem services. There are significant scientific challenges to understanding how these forces will interact to affect aquatic ecosystems, as the flow of energy and materials in the environment is driven by multivariate and non-linear biogeochemical cycles. The National Ecological Observatory Network (NEON) will collect and provide observational data across multiple scales. Sites were selected to maximize representation of major North American ecosystems using a multivariate geographic clustering method that partitioned the continental US, AK, HI, and Puerto Rico into 20 eco-climatic domains. The NEON data collection systems and methods are designed to yield standardized, near real-time data subjected to rigorous quality controls prior to public dissemination through an online data portal. NEON will collect data for 30 years to facilitate spatial-temporal analysis of environmental responses and drivers of ecosystem change, ranging from local through continental scales. Here we present the NEON Aquatic Network, a multi-parameter network consisting of a combination of in situ sensor and observational data. This network will provide data to examine biogeochemical, biological, hydrologic and geomorphic metrics at 36 sites, which are a combination of small 1st/2nd order wadeable streams, large rivers and lakes. A typical NEON Aquatic site will host up to two in-stream sensor sets designed to collect near-continuous water quality data (e.g. pH/ORP, temperature, conductivity, dissolved oxygen, CDOM) along with up to 8 shallow groundwater monitoring wells (level, temp., cond.), and a local meteorological station (e.g. 2D wind speed, PAR, barometric pressure, temperature, net radiation). These coupled sensor suites will be complemented by observational data (e.g. water

  7. First attempts towards an integrative concept for the ecological assessment of groundwater ecosystems

    Science.gov (United States)

    Steube, Christian; Richter, Simone; Griebler, Christian

    2009-02-01

    Healthy aquifers deliver important ecosystem services, e.g. the purification of infiltrating water and the storage of high-quality water over decades in significant quantities. The functioning of terrestrial and surface aquatic ecosystems directly depends on groundwater and vice versa. Nowadays, legislation has started to consider groundwater not only as a resource but as a living ecosystem. The assessment of ecosystems requires consideration of ecological criteria, which, so far, are not available for groundwater systems. In the framework of a project supported by the German Federal Environment Agency (UBA), a first concept for the ecological assessment of groundwater ecosystems is developed. Steps to be taken are introduced, with a strong focus on microbes as potential bioindicators. These include (1) the typology of groundwater ecosystems, (2) the derivation of natural background values, (3) the identification of potential bioindicators, and (4) the development of an assessment model. First successes and difficulties associated with these challenges, e.g. the lack of simple correlations between abiotic and biotic variables, are discussed on the basis of a data set from a local and regional aquifer in NE Germany. The need for collaboration between ecologists, hydrogeologists and geochemists, as well as the application of modern approaches such as multivariate statistics, is emphasized.

  8. Capturing multiple values of ecosystem services shaped by environmental worldviews: a spatial analysis.

    Science.gov (United States)

    Van Riper, Carena J; Kyle, Gerard T

    2014-12-01

    Two related approaches to valuing nature have been advanced in past research including the study of ecosystem services and psychological investigations of the factors that shape behavior. Stronger integration of the insights that emerge from these two lines of enquiry can more effectively sustain ecosystems, economies, and human well-being. Drawing on survey data collected from outdoor recreationists on Santa Cruz Island within Channel Islands National Park, U.S., our study blends these two research approaches to examine a range of tangible and intangible values of ecosystem services provided to stakeholders with differing biocentric and anthropocentric worldviews. We used Public Participation Geographic Information System methods to collect survey data and a Social Values for Ecosystem Services mapping application to spatially analyze a range of values assigned to terrestrial and aquatic ecosystems in the park. Our results showed that preferences for the provision of biological diversity, recreation, and scientific-based values of ecosystem services varied across a spatial gradient. We also observed differences that emerged from a comparison between survey subgroups defined by their worldviews. The implications emanating from this investigation aim to support environmental management decision-making in the context of protected areas.

  9. Diversity of Aquatic Insects in Keniam River, National Park, Pahang, Malaysia

    Directory of Open Access Journals (Sweden)

    Mohd Rasdi, Z.

    2012-09-01

    Full Text Available The study on biodiversity of aquatic insects was carried out covering the area of Kuala Keniam to Kuala Perkai River, National Park, Pahang, Malaysia. The macro invertebrate community was found in the different types of micro-habitat and various flowing speed levels in good quality of water of Keniam Rivers consisted mainly of aquatic insects. There are large numbers and wide species of aquatic insects in aquatic habitats make them of great ecological importance. There are three divided strata with total of nine sampling location were carried out within several varieties of microhabitats such as sandy, cobble, gravel, leaf and the pool area. The aquatic insects were collected and sampled by using a D-framed aquatic kick net. There was a wide variety of aquatic insects belonging to at least 8 orders in the study area. The orders of insect were Odonata, Coleoptera, Diptera, Trichoptera, Thysanura, Orthopthera, Hemiptera and Ephemeroptera. Throughout the study period, there is range from total of 140 to 604 individuals of aquatic insect trapped monthly and collected in Keniam River from September 2009 to December 2010. Some group of aquatic insects were found significant (χ2<0.05 different abundance between strata and sampling dates as well as habitat on the diversity of aquatic insects in Keniam River. The abundance and distribution of aquatic insects‟ species were varied and not constant from one month to another during the study period due to biotic and abiotic factors. Species diversity of aquatic insects varied in different strata of the Keniam River. This indicates the richness and diverse groups of aquatic insects in the study area. It adds to the fact that the undisturbed habitat quality is most suitable for insects to breed and multiply under the natural ecosystem with abundant food supply. Moving upstream from Kuala Perkai to lower stream to Kuala Keniam, one can observe various types of habitats for aquatic insects to live.

  10. Aquatic exercise & balneotherapy in musculoskeletal conditions.

    Science.gov (United States)

    Verhagen, Arianne P; Cardoso, Jefferson R; Bierma-Zeinstra, Sita M A

    2012-06-01

    This is a best-evidence synthesis providing an evidence-based summary on the effectiveness of aquatic exercises and balneotherapy in the treatment of musculoskeletal conditions. The most prevalent musculoskeletal conditions addressed in this review include: low back pain, osteoarthritis, fibromyalgia and rheumatoid arthritis. Over 30 years of research demonstrates that exercises in general, and specifically aquatic exercises, are beneficial for reducing pain and disability in many musculoskeletal conditions demonstrating small to moderate effect sizes ranging between 0.19 and 0.32. Balneotherapy might be beneficial, but the evidence is yet insufficient to make a definitive statement about its use. High-quality trials are needed on balneotherapy and aquatic exercises research especially in specific patient categories that might benefit most.

  11. Unravelling the role of allochthonous aquatic resources to food web structure in a tropical riparian forest.

    Science.gov (United States)

    Recalde, Fátima C; Postali, Thaís C; Romero, Gustavo Q

    2016-03-01

    The role of matter and energy flow across ecosystem boundaries for the subsidized consumer populations is well known. However, little is known on the effects of allochthonous subsidies on food web structure and trophic niche dimensions of consumers in the tropics. We excluded allochthonous aquatic insects from tropical streams using greenhouse-type exclosures to test the influence of aquatic allochthonous subsidies on the trophic structure and niche dimensions of terrestrial predators using stable isotope methods. In exclosure treatments, abundance and biomass of terrestrial predators, and biomass of phytophages decreased and increased, respectively. Vegetation-living predators were more responsive to allochthonous inputs than those living on the ground. Overall, lower availability of allochthonous inputs did not affect community-wide metrics and niche width of predators. However, the niche width of some spider families had very low overlap between treatments, and others had wider isotopic niches in the control than in the exclusion treatment. Most of the C and N in predators living in control stretches came from aquatic subsidies, and those predators living in the exclusion treatments switched their diets to terrestrial sources, showing a preference of predators for allochthonous subsidies. Our results suggest that allochthonous subsidies are also relevant to tropical fauna living upon vegetation. Moreover, allochthonous resources may amplify the niche dimension of certain predators or considerably change the trophic niche of others. Our study highlights the importance of including modern isotopic tools in elucidating the role of allochthonous resources on the patterns of trophic structure and niche dimensions of consumers from donor ecosystems.

  12. Scaling macroscopic aquatic locomotion

    Science.gov (United States)

    Gazzola, Mattia; Argentina, Mederic; Mahadevan, Lakshminarayanan

    2014-11-01

    Inertial aquatic swimmers that use undulatory gaits range in length L from a few millimeters to 30 meters, across a wide array of biological taxa. Using elementary hydrodynamic arguments, we uncover a unifying mechanistic principle characterizing their locomotion by deriving a scaling relation that links swimming speed U to body kinematics (tail beat amplitude A and frequency ω) and fluid properties (kinematic viscosity ν). This principle can be simply couched as the power law Re ~ Swα , where Re = UL / ν >> 1 and Sw = ωAL / ν , with α = 4 / 3 for laminar flows, and α = 1 for turbulent flows. Existing data from over 1000 measurements on fish, amphibians, larvae, reptiles, mammals and birds, as well as direct numerical simulations are consistent with our scaling. We interpret our results as the consequence of the convergence of aquatic gaits to the performance limits imposed by hydrodynamics.

  13. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    Science.gov (United States)

    Barrett, Katharine; Willard, Carolyn

    This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

  14. Aquatics Therapy and the Halliwick Concept

    Science.gov (United States)

    Skinner, Alison; Thomson, Ann

    2008-01-01

    Aquatic therapy is the use of the properties of water for the therapeutic benefit of people of all ages and abilities. This article illustrates how people with disabilities may maximize the benefits of activities in water, including individual and group work and swimming. The overall aim is to encourage family activity and social interaction. The…

  15. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  16. Complex Adaptive Digital EcoSystems

    CERN Document Server

    Briscoe, Gerard

    2011-01-01

    We investigate an abstract conceptualisation of DigitalEcosystems from a computer science perspective. We then provide a conceptual framework for the cross pollination of ideas, concepts and understanding between different classes of ecosystems through the universally applicable principles of Complex Adaptive Systems (CAS) modelling. A framework to assist the cross-disciplinary collaboration of research into Digital Ecosystems, including Digital BusinessEcosystems (DBEs) and Digital Knowledge Ecosystems (DKEs). So, we have defined the key steps towards a theoretical framework for Digital Ecosystems, that is compatible with the diverse theoretical views prevalent. Therefore, a theoretical edifice that can unify the diverse efforts within Digital Ecosystems research.

  17. Risks of large-scale use of systemic insecticides to ecosystem functioning and services.

    Science.gov (United States)

    Chagnon, Madeleine; Kreutzweiser, David; Mitchell, Edward A D; Morrissey, Christy A; Noome, Dominique A; Van der Sluijs, Jeroen P

    2015-01-01

    Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the context of valuing the service potentials, benefits, and use values that well-functioning ecosystems provide to humans and the biosphere and, as an endpoint (value to be protected), in ecological risk assessment of chemicals. Neonicotinoid insecticides are frequently detected in soil and water and are also found in air, as dust particles during sowing of crops and aerosols during spraying. These environmental media provide essential resources to support biodiversity, but are known to be threatened by long-term or repeated contamination by neonicotinoids and fipronil. We review the state of knowledge regarding the potential impacts of these insecticides on ecosystem functioning and services provided by terrestrial and aquatic ecosystems including soil and freshwater functions, fisheries, biological pest control, and pollination services. Empirical studies examining the specific impacts of neonicotinoids and fipronil to ecosystem services have focused largely on the negative impacts to beneficial insect species (honeybees) and the impact on pollination service of food crops. However, here we document broader evidence of the effects on ecosystem functions regulating soil and water quality, pest control, pollination, ecosystem resilience, and community diversity. In particular, microbes, invertebrates, and fish play critical roles as decomposers, pollinators, consumers, and predators, which collectively maintain healthy communities and ecosystem integrity. Several examples in this review demonstrate evidence of the negative impacts of systemic insecticides on decomposition, nutrient cycling, soil respiration, and invertebrate populations valued by humans. Invertebrates

  18. Internal nitrogen removal from sediments by the hybrid system of microbial fuel cells and submerged aquatic plants

    Science.gov (United States)

    Xu, Peng; Xiao, En-Rong; Xu, Dan; Zhou, Yin; He, Feng; Liu, Bi-Yun; Zeng, Lei; Wu, Zhen-Bin

    2017-01-01

    Sediment internal nitrogen release is a significant pollution source in the overlying water of aquatic ecosystems. This study aims to remove internal nitrogen in sediment-water microcosms by coupling sediment microbial fuel cells (SMFCs) with submerged aquatic plants. Twelve tanks including four treatments in triplicates were designed: open-circuit (SMFC-o), closed-circuit (SMFC-c), aquatic plants with open-circuit (P-SMFC-o) and aquatic plants with closed-circuit (P-SMFC-c). The changes in the bio-electrochemical characteristics of the nitrogen levels in overlying water, pore water, sediments, and aquatic plants were documented to explain the migration and transformation pathways of internal nitrogen. The results showed that both electrogenesis and aquatic plants could facilitate the mineralization of organic nitrogen in sediments. In SMFC, electrogenesis promoted the release of ammonium from the pore water, followed by the accumulation of ammonium and nitrate in the overlying water. The increased redox potential of sediments due to electrogenesis also contributed to higher levels of nitrate in overlying water when nitrification in pore water was facilitated and denitrification at the sediment-water interface was inhibited. When the aquatic plants were introduced into the closed-circuit SMFC, the internal ammonium assimilation by aquatic plants was advanced by electrogenesis; nitrification in pore water and denitrification in sediments were also promoted. These processes might result in the maximum decrease of internal nitrogen with low nitrogen levels in the overlying water despite the lower power production. The P-SMFC-c reduced 8.1%, 16.2%, 24.7%, and 25.3% of internal total nitrogen compared to SMFC-o on the 55th, 82th, 136th, and 190th days, respectively. The smaller number of Nitrospira and the larger number of Bacillus and Pseudomonas on the anodes via high throughput sequencing may account for strong mineralization and denitrification in the sediments

  19. Internal nitrogen removal from sediments by the hybrid system of microbial fuel cells and submerged aquatic plants.

    Science.gov (United States)

    Xu, Peng; Xiao, En-Rong; Xu, Dan; Zhou, Yin; He, Feng; Liu, Bi-Yun; Zeng, Lei; Wu, Zhen-Bin

    2017-01-01

    Sediment internal nitrogen release is a significant pollution source in the overlying water of aquatic ecosystems. This study aims to remove internal nitrogen in sediment-water microcosms by coupling sediment microbial fuel cells (SMFCs) with submerged aquatic plants. Twelve tanks including four treatments in triplicates were designed: open-circuit (SMFC-o), closed-circuit (SMFC-c), aquatic plants with open-circuit (P-SMFC-o) and aquatic plants with closed-circuit (P-SMFC-c). The changes in the bio-electrochemical characteristics of the nitrogen levels in overlying water, pore water, sediments, and aquatic plants were documented to explain the migration and transformation pathways of internal nitrogen. The results showed that both electrogenesis and aquatic plants could facilitate the mineralization of organic nitrogen in sediments. In SMFC, electrogenesis promoted the release of ammonium from the pore water, followed by the accumulation of ammonium and nitrate in the overlying water. The increased redox potential of sediments due to electrogenesis also contributed to higher levels of nitrate in overlying water when nitrification in pore water was facilitated and denitrification at the sediment-water interface was inhibited. When the aquatic plants were introduced into the closed-circuit SMFC, the internal ammonium assimilation by aquatic plants was advanced by electrogenesis; nitrification in pore water and denitrification in sediments were also promoted. These processes might result in the maximum decrease of internal nitrogen with low nitrogen levels in the overlying water despite the lower power production. The P-SMFC-c reduced 8.1%, 16.2%, 24.7%, and 25.3% of internal total nitrogen compared to SMFC-o on the 55th, 82th, 136th, and 190th days, respectively. The smaller number of Nitrospira and the larger number of Bacillus and Pseudomonas on the anodes via high throughput sequencing may account for strong mineralization and denitrification in the sediments

  20. Potential effects of climate change on freshwater ecosystems of the New England/Mid-Atlantic Region

    Science.gov (United States)

    Moore, M.V.; Pace, M.L.; Mather, J.R.; Murdoch, Peter S.; Howarth, R.W.; Folt, C.L.; Chen, C.-Y.; Hemond, Harold F.; Flebbe, P.A.; Driscoll, C.T.

    1997-01-01

    ameliorated. Recommendations for future monitoring efforts include: (1) extending and improving data on the distribution, abundance and effect of anthropogenic Stressors (non-point pollution) within the region; and (2) improving scientific knowledge regarding the contemporary distribution and abundance of aquatic species. Research recommendations include: (1) establishing a research centre(s) where field studies designed to understand interactions between freshwater ecosystems and climate change can be conducted; (2) projecting the future distribution, activities and direct effects of humans within the region; (3) developing mathematical analyses, experimental designs and aquatic indicators that distinguish between climatic and anthropogenic effects on aquatic systems; (4) developing and refining projections of climate variability such that the magnitude, frequency and seasonal timing of extreme events can be forecast; and (5) describing quantitatively the flux of materials (sediments, nutrients, metals) from watersheds characterized by a mosaic of land uses. ?? 1997 by John Wiley & Sons, Ltd.

  1. 77 FR 49601 - Endangered and Threatened Wildlife and Plants; Endangered Status for Six West Texas Aquatic...

    Science.gov (United States)

    2012-08-16

    ... and Threatened Wildlife and Plants; Endangered Status for Six West Texas Aquatic Invertebrate Species... endemic species of fish, plants, mollusks, and crustaceans, including the six endemic aquatic invertebrate... flowing by 1962 (Brune 1981, p. 358), eliminating all aquatic-dependent plants and animals (Scudday...

  2. Application of portable in situ UV fluorescence sensors in natural and engineered aquatic systems.

    Science.gov (United States)

    Fox, Bethany; Rushworth, Cathy; Atrridge, John

    2016-04-01

    Natural organic matter (NOM) is ubiquitous throughout aquatic systems. This heterogeneous mixture of organic matter is central for aquatic ecosystems and, both local and global, biogeochemical cycling. Improvements in technology and data analysis has allowed for advances in the understanding and characterisation of aquatic organic matter. However, much of the technological expansions have focussed on benchtop instruments. In recent years, there has been interest in the continued development of portable in situ sensors for monitoring NOM characteristics within a wide range of applications, spanning both natural and engineered systems. The UviLux (Chelsea Technologies Group Ltd., UK) is an in situ portable UV fluorescence sensor that can be configured to monitor a range of NOM in aquatic systems, as well as anthropogenic inputs such as polycyclic aromatic hydrocarbons (PAH) and optical brighteners. Here we will focus on the use of the Tryptophan and CDOM UviLux sensors across a variety of applications in both natural systems, such as rivers and leachate into groundwater, and engineered systems, including drinking water and waste water treatment. Recent work has focused on standardising the fluorescence output across the UviLux range of sensors, reporting data in quinine sulphate units (QSU), which enables the output from two different fluorometers to be directly compared both to each other, and to bench-top data. A key advantage of deploying multiple sensors is the ability to fingerprint the fluorescence, by providing, for example, a Tryptophan/CDOM ratio. From the data collected, the ratio of the different fluorescence regions has been shown to provide more robust in situ data and help identify true temporal variations and patterns across multiple applications and sampling locations.

  3. Aquatic ecotoxicology: what has been accomplished and what lies ahead? An Eastern Canada historical perspective

    Directory of Open Access Journals (Sweden)

    Christian Blaise

    2013-10-01

    Full Text Available Our recent history shows that degradation of aquatic ecosystems essentially stems from industrialization, urbanization and increasing human populations. After a first industrial boom in the late 19th century, contamination pressures on receiving waters now appear to be continual because of expanding economies and technologies developing at the planetary scale. Given the diversity of issues, problems and challenges facing water quality today because of complex waste and chemical discharges into waterways, aquatic ecotoxicology has blossomed with time into a more mature discipline of the environmental sciences. Its two fundamental pillars, bioassays and biomarkers, have become essential tools that allow the determination of numerous and versatile effects measurements. Herein, we demonstrate some of the ways in which thesetools have been applied and how they have evolved over the past decades to appraise the ecotoxicity of contaminants impacting aquatic systems. Examples discussed are largely reflective of work conducted in the Environment Canada (EC laboratories (Saint-Lawrence Centre, Montréal, Canada. Success stories include improvement of industrial effluent quality contributing to beluga whale population recovery in the Saint-Lawrence River, biomarker field studies conducted with endemic and caged bivalves to more fully comprehend urban effluent adverse effects, and increased discernment on the hazard potential posed by emerging classes of chemicals. Ecotoxicology continues to be confronted with diverse issues and needs related to a myriad of chemical contaminants released to aquatic environments worldwide. To cope with these, ecotoxicology will have to bank on new tools (e.g., toxicogenomics, bio-informatics, modelingand become more interdisciplinary by taking into account knowledge provided by other disciplines (e.g., ecology, chemistry, climatology, microbiology in order to more fully understand and adequately interpret hazard. This will

  4. Designer ecosystems

    NARCIS (Netherlands)

    Awasthi, Ashutosh; Singh, Kripal; O'Grady, Audrey; Courtney, Ronan; Kalra, Alok; Singh, Rana Pratap; Cerda Bolinches, Artemio; Steinberger, Yosef; Patra, D.D.

    2016-01-01

    Increase in human population is accelerating the rate of land use change, biodiversity loss and habitat degradation, triggering a serious threat to life supporting ecosystem services. Existing strategies for biological conservation remain insufficient to achieve a sustainable human-nature relatio

  5. Remote sensing of aquatic vegetation: theory and applications.

    Science.gov (United States)

    Silva, Thiago S F; Costa, Maycira P F; Melack, John M; Novo, Evlyn M L M

    2008-05-01

    Aquatic vegetation is an important component of wetland and coastal ecosystems, playing a key role in the ecological functions of these environments. Surveys of macrophyte communities are commonly hindered by logistic problems, and remote sensing represents a powerful alternative, allowing comprehensive assessment and monitoring. Also, many vegetation characteristics can be estimated from reflectance measurements, such as species composition, vegetation structure, biomass, and plant physiological parameters. However, proper use of these methods requires an understanding of the physical processes behind the interaction between electromagnetic radiation and vegetation, and remote sensing of aquatic plants have some particular difficulties that have to be properly addressed in order to obtain successful results. The present paper reviews the theoretical background and possible applications of remote sensing techniques to the study of aquatic vegetation.

  6. Social network analysis on mangrove ecosystem management of Welu Basin, Thailand

    Directory of Open Access Journals (Sweden)

    Thak Thongphubate

    2016-06-01

    Full Text Available The use of social network for support mangrove ecosystem management in terms of proposed policy was studied. The results show that most samples, live in Baan Si Lamtian and Baan Paaknam Welu. Majorities of samples are women in the age range of 51-60 years old and they are fishery and have own business, respectively. The social network characteristics are the center person of the network who is the mainstay of Baan Nagoong and close-by the person on a network cultivating farmers group of Baan Si Lamtian. Two main proposed policies are hastening to the control of encroach on forests, fishing gears uses and illegal germinate aquatic animals. In addition, information including coincide planning with fishermen who set the fish traps and specify Tambon Bangchan to be the special area for aquatics management were proposed by setting the measurement with community for farm control and cultivate plot which caused shallow in the basin.

  7. State of the Crown of the continent ecosystem : Flathead/Castle Transboundary Bioregion (draft)

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, E.; Peck, B.; Stewart, A.; Stewart, C.

    1999-01-01

    This state of the ecosystem report describes the ecological composition of the Flathead/Castle Transboundary bioregion, including human activity. The ecosystem (which does not follow political boundaries) extends from western Alberta, eastern British Columbia and Montana. The region encompasses 5088 square km. and occupies two watersheds of the greater Crown of the Continent Ecosystem. Ecological components of the North Fork of the Flathead and of the Castle Drainage including such ecological processes as fire and disease, vegetation, species, wildlife, the aquatic environment, and a century of human activity in the two regions are described. Forestry practices, petroleum extraction, mining, recreational activities, land development, ranching practices, and road development in the two regions are reviewed, along with ecosystem-wide trends. The advantages of ecosystem based management integrated with human based management practices was demonstrated by describing the Rocky Mountain Grizzly Bear Planning Committee`s work . The Committee consists of representatives of wildlife agencies of Montana, BC, Alberta and Canadian and US federal government agencies who share responsibility for jointly mapping grizzly habitat, grizzly mortality sinks, pooling data on mortalities to ensure that the regional grizzly bear population is managed as one population regardless of political boundaries. 221 refs., tabs., figs.

  8. AQUATOX coupled foodweb model for ecosystem risk assessment of Polybrominated diphenyl ethers (PBDEs) in lake ecosystems.

    Science.gov (United States)

    Zhang, Lulu; Liu, Jingling

    2014-08-01

    The AQUATOX model considers the direct toxic effects of chemicals and their indirect effects through foodwebs. For this study, the AQUATOX model was applied to evaluating the ecological risk of Polybrominated diphenyl ethers (PBDEs) in a highly anthropogenically disturbed lake-Baiyangdian Lake. Calibration and validation results indicated that the model can adequately describe the dynamics of 18 biological populations. Sensitivity analysis results suggested that the model is highly sensitive to temperature limitation. PBDEs risk estimate results demonstrate that estimated risk for natural ecosystems cannot be fully explained by single species toxicity data alone. The AQUATOX model could provide a good basis in ascertaining ecological protection levels of "chemicals of concern" for aquatic ecosystems. Therefore, AQUATOX can potentially be used to provide necessary information corresponding to early warning and rapid forecasting of pollutant transport and fate in the management of chemicals that put aquatic ecosystems at risk.

  9. Remote Sensing of Aquatic Vegetation Coverage in the Kafue River, Zambia and Comparison to Climatic Variables

    Science.gov (United States)

    Mischler, J. A.; Abdalati, W.; Hussein, K.; Townsend, A. R.

    2013-12-01

    The Kafue River is the longest river in Zambia and is a major tributary of the Zambezi River. It is a vital source of fish, transportation, drinking water, and hydropower for much of Zambia's population, over half of whom live in the Kafue River basin. Like many important water bodies in developing countries the Kafue and its ecosystems face pollution from industrial, mining, agricultural, and domestic/sewage discharge. The Kafue River forms a wide and shallow wetland (the Kafue Flats) during the rainy season (Nov. - Apr.) which serves as habitat for diverse groups of birds and mammals. In recent years the unprecedented emergence of invasive aquatic vegetation such as the water hyacinth (Eichhornia crassipes) and Salvinia molesta have choked the river, degrading its ability to provide adequate habitat to promote biodiversity, ecosystem services, and hydropower. In addition, these plants provide additional habitat for mosquitoes (vectors for malaria) and aquatic snails (vectors of schistosomiasis). Nutrient-rich effluents are widely believed to contribute to the proliferation and explosive growth of this floating aquatic vegetation. The general methods for managing these aquatic weeds have included mechanical and physical removal, herbicides, and bio-control agents which have had very little impact. However, as in neighboring Lake Victoria, total weed coverage has fluctuated dramatically from year to year making evaluation of the efficacy of management programs difficult. The objectives of this study were to (1) generate the first record of aquatic plant coverage for a section of the Kafue River which is immediately downstream of a sugar plantation (a major source of nitrogen and phosphorus to the river) and (2) determine if plant coverage is correlated with any major climatic (ENSO, temperature, rainfall) or management (introduction of bio-control agents) indices. We utilized remote sensing techniques in conjunction with Landsat 4-5 TM and Landsat 7 ETM imagery for

  10. Assessing the effects of chemicals on aquatic microbial ecosystems

    NARCIS (Netherlands)

    Rocha Dimitrov, M.

    2016-01-01

    Nowadays, an increasing number of synthetic chemicals are used in a vast range of applications. When reflecting about our daily activities, it is not difficult to realize how much of our life style is dependent on synthetic chemicals. From the food we eat, medicines we take to the health care produc

  11. Bioaccumulation factors in aquatic ecosystems. A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Sara; Meili, Markus; Bergstroem, Ulla [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    2002-07-01

    The calculated concentrations of radionuclides in organisms are often obtained by means of bioaccumulation factors (BAF) that describe the internal concentration relative to an external concentration e.g. in the abiotic environments at steady-state conditions. Such factors are often used when modelling the dose to man from radio-nuclides released to the biosphere. Values of bioaccumulation factors vary widely in magnitude among elements, organisms, and environmental conditions which is not always considered. In order to relate the bioaccumulation factors for some radionuclides to environmental conditions as well as to the trophic level of the organism of concern we have compiled an extensive database with bioaccumulation factors (about 5,500 values) together with information on some environmental conditions. The data for nine radionuclides has been extracted and examined. A comparison between the bioaccumulation factors found in this study and values given in literature by IAEA and NCRP shows that the ranges presented in this study are generally somewhat higher with the exception of BAF for molybdenum in freshwater fish which is of the same order of magnitude. This is startling and calls for a thorough research. The amount of readily accessible and reliable values of BAF is limited, often because basic information such as e.g. units and part of organism examined, is not reported. This is surprising and also unfortunate for those who need such data for use in generic or specific models. A major update of recommended values appears to be necessary for many elements to account for the development of analytical methods and experiences from case studies over the past two decades.

  12. Community and ecosystem responses to a pulsed pesticide disturbance in freshwater ecosystems.

    Science.gov (United States)

    Downing, Amy L; DeVanna, Kristen M; Rubeck-Schurtz, C Nichole; Tuhela, Laura; Grunkemeyer, Heather

    2008-08-01

    Pesticides have been shown to be detrimental to key groups of freshwater organisms including cladocerans, odonates, and amphibians. However, less is known about the response of freshwater communities and ecosystems to pesticide disturbances as they occur in nature. Using outdoor aquatic mesocosms, we assembled identical and diverse replicate freshwater plankton food webs obtained from an adjacent pond. We established three pesticide treatments consisting of pulses of a common pesticide Sevin with the active ingredient carbaryl, at concentrations of 0.1, 1 and 20 microg carbaryl/ml, and a pesticide-free control treatment. We monitored the response of microbial, phytoplankton, and zooplankton communities in addition to oxygen concentrations. Carbaryl concentrations peaked shortly after Sevin application and degraded quickly and treatment differences were undetectable after 30 days. Zooplankton richness, diversity, abundance, and oxygen concentrations all decreased in pulsed treatments, while phytoplankton and microbial abundance increased. Zooplankton composition in the high pesticide treatment consisted primarily of rotifers as compared to dominance by copepods in the other three treatments. While many of the community and ecosystem properties showed signs of recovery within 40 days after the pulsed pesticide disturbance, important and significant differences remained in the microbial, phytoplankton and zooplankton communities after the pesticide degraded.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mao Huan; Wang Dahui [Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China); Yang Wanxi, E-mail: wxyang@spermlab.org [Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058 (China)

    2012-04-15

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

  14. Effects of cement flue dust from a cement factory on stress parameters and diversity of aquatic plants.

    Science.gov (United States)

    Erdal, Serkan; Demirtas, Ayten

    2010-07-01

    Cement kiln dusts, made of a complex mixture of elements, include high levels of heavy metals such as fluoride, magnesium, lead, cadmium, nickel, zinc, copper, beryllium and some toxic compounds. Because of the toxic element compositions and radioactive isotope properties of cement kiln dusts, not only terrestrial but also aquatic ecosystems are subjected to greater stress. In the present paper, we investigated the effects of pollution caused by Askale-Erzurum cement factory (CF) on the stress parameters and diversity of aquatic plants. For this purpose, aquatic plant species were collected from the outer zone of the CF. Only three (Lemna minor, Ceratophyllum submersum and Potamogeton natans) of these species were able to be determined in the CF zone. Antioxidant enzyme activities of the collected aquatic plants were measured and compared to their controls. Superoxide dismutase (SOD) activity of P. natans in the CF zone was significantly high compared to their respective control, while it was low in L. minor and C. submersum compared to their controls. Similarly, peroxidase (POX) activity of P. natans was high, while those of L. minor and C. submersum were low compared to their respective controls. On the other side, while catalase (CAT) activities of L. minor and C. submersum were low, that of P. natans did not show an important change compared to their respective controls. Furthermore, we found that hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA) levels of all the studied plants were also very high compared to their controls. According to these results, it is clear that pollution caused by the CF reduced diversity and number of aquatic plant species. Besides, the obtained data revealed that P. natans have a more resistant defense system than other species.

  15. Temporal development of coastal ecosystems in the Baltic Sea - an assessment of patterns and trends

    DEFF Research Database (Denmark)

    Olsson, Jens; Bergström, Lena; Tomczak, Maciej;

    2014-01-01

    Coastal areas are amongst the most biologically productive aquatic systems worldwide, but face strong and varaible anthropogenic pressures. Many marine ecosystems worlwide has gone through substantial structural changes during recent decades, but few studies have addressed the temporal developmen...

  16. Metabolism of mineral-sorbed organic matter and microbial lifestyles in fluvial ecosystems

    NARCIS (Netherlands)

    Hunter, W.R.; Niederdorfer, R.; Gernand, A.; Veuger, B.; Prommer, J.; Mooshammer, M.; Wanek, W.; Battin, T.J.

    2016-01-01

    In fluvial ecosystems mineral erosion, carbon (C), and nitrogen (N) fluxes are linked via organomineral complexation, where dissolved organic molecules bind to mineral surfaces. Biofilms and suspended aggregates represent major aquatic microbial lifestyles whose relative importance changes predictab

  17. Biology of Applied Digital Ecosystems

    CERN Document Server

    Briscoe, G; Paperin, G

    2007-01-01

    A primary motivation for research in digital ecosystems is the desire to exploit the self-organising properties of natural ecosystems. Ecosystems are thought to be robust, scalable architectures that can automatically solve complex, dynamic problems. However, the biological processes that contribute to these properties have not been made explicit in digital ecosystem research. Here, we discuss how biological properties contribute to the self-organising features of natural ecosystems. These properties include populations of evolving agents, a complex dynamic environment, and spatial distributions which generate local interactions. The potential for exploiting these properties in artificial systems is then considered. An example architecture, the Digital Business Ecosystem (DBE), is considered in detail. Simulation results imply that the DBE performs better at large scales than a comparable service-oriented architecture. These results suggest that incorporating ideas from theoretical ecology can contribute to u...

  18. Methane emissions to the atmosphere through aquatic plants

    Science.gov (United States)

    Sebacher, D. I.; Harriss, R. C.; Bartlett, K. B.

    1985-01-01

    The movement of methane (CH4) from anaerobic sediments through the leaves, stems, and flowers of aquatic plants and into the atmosphere was found to provide a significant pathway for the emission of CH4 from the aquatic substrates of flooded wetlands. Methane concentrations well above the surrounding ambient air levels were found in the mesophyll of 16 varies of aquatic plants and are attributed to transpiration, diffusion, and pressure-induced flow of gaseous CH4 from the roots when they are embedded in CH4-saturated anaerobic sediments. Methane emissions from the emergent parts of aquatic plants were measured using floating chamber techniques and by enclosing the plants in polyethylene bags of known volume. Concentration changes were monitored in the trapped air using syringes and gas chromatographic techniques. Vertical profiles of dissolved CH4 in sediment pore water surrounding the aquatic plants' rhizomes were obtained using an interstitial sampling technique. Methane emissions from the aquatic plants studied varied from 14.8 mg CH4/d to levels too low to be detectable. Rooted and unrooted freshwater aquatic plants were studied as well as saltwater and brackish water plants. Included in the experiment is detailed set of measurements on CH4 emissions from the common cattail (Typha latifolia). This paper illustrates that aquatic plants play an important gas exchange role in the C cycle between wetlands and the atmosphere.

  19. Pain in aquatic animals.

    Science.gov (United States)

    Sneddon, Lynne U

    2015-04-01

    Recent developments in the study of pain in animals have demonstrated the potential for pain perception in a variety of wholly aquatic species such as molluscs, crustaceans and fish. This allows us to gain insight into how the ecological pressures and differential life history of living in a watery medium can yield novel data that inform the comparative physiology and evolution of pain. Nociception is the simple detection of potentially painful stimuli usually accompanied by a reflex withdrawal response, and nociceptors have been found in aquatic invertebrates such as the sea slug Aplysia. It would seem adaptive to have a warning system that allows animals to avoid life-threatening injury, yet debate does still continue over the capacity for non-mammalian species to experience the discomfort or suffering that is a key component of pain rather than a nociceptive reflex. Contemporary studies over the last 10 years have demonstrated that bony fish possess nociceptors that are similar to those in mammals; that they demonstrate pain-related changes in physiology and behaviour that are reduced by painkillers; that they exhibit higher brain activity when painfully stimulated; and that pain is more important than showing fear or anti-predator behaviour in bony fish. The neurophysiological basis of nociception or pain in fish is demonstrably similar to that in mammals. Pain perception in invertebrates is more controversial as they lack the vertebrate brain, yet recent research evidence confirms that there are behavioural changes in response to potentially painful events. This review will assess the field of pain perception in aquatic species, focusing on fish and selected invertebrate groups to interpret how research findings can inform our understanding of the physiology and evolution of pain. Further, if we accept these animals may be capable of experiencing the negative experience of pain, then the wider implications of human use of these animals should be considered.

  20. Direct and indirect effects of glaciers on aquatic biodiversity in high Andean peatlands

    DEFF Research Database (Denmark)

    Quenta, Estefania; Molina-Rodriguez, Jorge; Gonzales, Karina

    2016-01-01

    The rapid melting of glacier cover is one of the most obvious impacts of climate change on alpine ecosystems and biodiversity. Our understanding of the impact of a decrease in glacier runoff on aquatic biodiversity is currently based on the 'glacier-heterogeneity-diversity' paradigm, according....... These findings provide new insight into the potential effects of glacial retreat on the aquatic environment and biodiversity in the peatlands of the tropical Andes....

  1. Microbial nitrous oxide production and nitrogen cycling associated with aquatic invertebrates

    OpenAIRE

    Heisterkamp, Ines

    2012-01-01

    Nitrogen cycling is intimately linked to the activity of microorganisms that mediate the diverse nitrogen transformations and play a fundamental role in regulating the fate of nitrogen in the Earth s terrestrial and aquatic ecosystems. Microbial activity is influenced by physical, chemical, and biological factors that can be profoundly shaped by macrofaunal organisms, especially in benthic aquatic systems. This thesis therefore aimed at investigating the interactions between microorganisms an...

  2. Disordered eating and eating disorders in aquatic sports

    DEFF Research Database (Denmark)

    Melin, Anna; Torstveit, Monica Klungland; Burke, Louise

    2014-01-01

    -demanding sports have an increased risk for RED-S and for developing EDs/DE. Special risk factors in aquatic sports related to weight and body composition management include the wearing of skimpy and tight-fitting bathing suits, and in the case of diving and synchronized swimming, the involvement of subjective...... judgements of performance. The reported prevalence of DE and EDs in athletic populations including athletes from aquatic sports ranges from 18-45 % in female athletes and 0-28 % in male athletes. To prevent EDs, aquatic athletes should practice healthy eating behaviour at all periods of development pathway...

  3. Journal Articles Applying National Aquatic Resource Survey Data

    Science.gov (United States)

    The National Aquatic Resource Surveys (NARS) data are being used and applied above and beyond the regional and national assessments. This page includes a list of recent journal articles that reference NARS data.

  4. Visualizing aquatic bacteria by light and transmission electron microscopy.

    Science.gov (United States)

    Silva, Thiago P; Noyma, Natália P; Duque, Thabata L A; Gamalier, Juliana P; Vidal, Luciana O; Lobão, Lúcia M; Chiarini-Garcia, Hélio; Roland, Fábio; Melo, Rossana C N

    2014-01-01

    The understanding of the functional role of aquatic bacteria in microbial food webs is largely dependent on methods applied to the direct visualization and enumeration of these organisms. While the ultrastructure of aquatic bacteria is still poorly known, routine observation of aquatic bacteria by light microscopy requires staining with fluorochromes, followed by filtration and direct counting on filter surfaces. Here, we used a new strategy to visualize and enumerate aquatic bacteria by light microscopy. By spinning water samples from varied tropical ecosystems in a cytocentrifuge, we found that bacteria firmly adhere to regular slides, can be stained by fluorochoromes with no background formation and fast enumerated. Significant correlations were found between the cytocentrifugation and filter-based methods. Moreover, preparations through cytocentrifugation were more adequate for bacterial viability evaluation than filter-based preparations. Transmission electron microscopic analyses revealed a morphological diversity of bacteria with different internal and external structures, such as large variation in the cell envelope and capsule thickness, and presence or not of thylakoid membranes. Our results demonstrate that aquatic bacteria represent an ultrastructurally diverse population and open avenues for easy handling/quantification and better visualization of bacteria by light microscopy without the need of filter membranes.

  5. Effect of pesticides on microbial communities in container aquatic habitats

    Science.gov (United States)

    Muturi, Ephantus J.; Donthu, Ravi Kiran; Fields, Christopher J.; Moise, Imelda K.; Kim, Chang-Hyun

    2017-01-01

    Container aquatic habitats support a specialized community of macroinvertebrates (e.g. mosquitoes) that feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to pesticides. We used a microcosm approach to examine the single and combined effects of two herbicides (atrazine, glyphosate), and three insecticides (malathion, carbaryl, permethrin) on microbial communities of container aquatic habitats. MiSeq sequencing of the V4 region of both bacterial and archaeal 16S rRNA gene was used to characterize the microbial communities of indoor microcosms that were either exposed to each pesticide alone, a mix of herbicides, a mix of insecticides, or a mix of all five insecticides. Individual insecticides but not herbicides reduced the microbial diversity and richness and two insecticides, carbaryl and permethrin, also altered the microbial community structure. A mixture of herbicides had no effect on microbial diversity or structure but a mixture of insecticides or all five pesticides reduced microbial diversity and altered the community structure. These findings suggest that exposure of aquatic ecosystems to individual pesticides or their mixtures can disrupt aquatic microbial communities and there is need to decipher how these changes affect resident macroinvertebrate communities. PMID:28300212

  6. Molecular Barcoding of Aquatic Oligochaetes: Implications for Biomonitoring

    Science.gov (United States)

    Vivien, Régis; Wyler, Sofia; Lafont, Michel; Pawlowski, Jan

    2015-01-01

    Aquatic oligochaetes are well recognized bioindicators of quality of sediments and water in watercourses and lakes. However, the difficult taxonomic determination based on morphological features compromises their more common use in eco-diagnostic analyses. To overcome this limitation, we investigated molecular barcodes as identification tool for broad range of taxa of aquatic oligochaetes. We report 185 COI and 52 ITS2 rDNA sequences for specimens collected in Switzerland and belonging to the families Naididae, Lumbriculidae, Enchytraeidae and Lumbricidae. Phylogenetic analyses allowed distinguishing 41 lineages separated by more than 10 % divergence in COI sequences. The lineage distinction was confirmed by Automatic Barcode Gap Discovery (ABGD) method and by ITS2 data. Our results showed that morphological identification underestimates the oligochaete diversity. Only 26 of the lineages could be assigned to morphospecies, of which seven were sequenced for the first time. Several cryptic species were detected within common morphospecies. Many juvenile specimens that could not be assigned morphologically have found their home after genetic analysis. Our study showed that COI barcodes performed very well as species identifiers in aquatic oligochaetes. Their easy amplification and good taxonomic resolution might help promoting aquatic oligochaetes as bioindicators for next generation environmental DNA biomonitoring of aquatic ecosystems. PMID:25856230

  7. Effect of pesticides on microbial communities in container aquatic habitats.

    Science.gov (United States)

    Muturi, Ephantus J; Donthu, Ravi Kiran; Fields, Christopher J; Moise, Imelda K; Kim, Chang-Hyun

    2017-03-16

    Container aquatic habitats support a specialized community of macroinvertebrates (e.g. mosquitoes) that feed on microbial communities associated with decaying organic matter. These aquatic habitats are often embedded within and around agricultural lands and are frequently exposed to pesticides. We used a microcosm approach to examine the single and combined effects of two herbicides (atrazine, glyphosate), and three insecticides (malathion, carbaryl, permethrin) on microbial communities of container aquatic habitats. MiSeq sequencing of the V4 region of both bacterial and archaeal 16S rRNA gene was used to characterize the microbial communities of indoor microcosms that were either exposed to each pesticide alone, a mix of herbicides, a mix of insecticides, or a mix of all five insecticides. Individual insecticides but not herbicides reduced the microbial diversity and richness and two insecticides, carbaryl and permethrin, also altered the microbial community structure. A mixture of herbicides had no effect on microbial diversity or structure but a mixture of insecticides or all five pesticides reduced microbial diversity and altered the community structure. These findings suggest that exposure of aquatic ecosystems to individual pesticides or their mixtures can disrupt aquatic microbial communities and there is need to decipher how these changes affect resident macroinvertebrate communities.

  8. Mapping cultural ecosystem services:

    DEFF Research Database (Denmark)

    Paracchini, Maria Luisa; Zulian, Grazia; Kopperoinen, Leena

    2014-01-01

    is required to address the issue, since by definition cultural services (encompassing physical, intellectual, spiritual interactions with biota) need to be analysed from multiple perspectives (i.e. ecological, social, behavioural). A second reason is the lack of data for large-scale assessments, as detailed......Research on ecosystem services mapping and valuing has increased significantly in recent years. However, compared to provisioning and regulating services, cultural ecosystem services have not yet been fully integrated into operational frameworks. One reason for this is that transdisciplinarity...... surveys are a main source of information. Among cultural ecosystem services, assessment of outdoor recreation can be based on a large pool of literature developed mostly in social and medical science, and landscape and ecology studies. This paper presents a methodology to include recreation...

  9. Improving the precision of lake ecosystem metabolism estimates by identifying predictors of model uncertainty

    Science.gov (United States)

    Rose, Kevin C.; Winslow, Luke A.; Read, Jordan S.; Read, Emily K.; Solomon, Christopher T.; Adrian, Rita; Hanson, Paul C.

    2014-01-01

    Diel changes in dissolved oxygen are often used to estimate gross primary production (GPP) and ecosystem respiration (ER) in aquatic ecosystems. Despite the widespread use of this approach to understand ecosystem metabolism, we are only beginning to understand the degree and underlying causes of uncertainty for metabolism model parameter estimates. Here, we present a novel approach to improve the precision and accuracy of ecosystem metabolism estimates by identifying physical metrics that indicate when metabolism estimates are highly uncertain. Using datasets from seventeen instrumented GLEON (Global Lake Ecological Observatory Network) lakes, we discovered that many physical characteristics correlated with uncertainty, including PAR (photosynthetically active radiation, 400-700 nm), daily variance in Schmidt stability, and wind speed. Low PAR was a consistent predictor of high variance in GPP model parameters, but also corresponded with low ER model parameter variance. We identified a threshold (30% of clear sky PAR) below which GPP parameter variance increased rapidly and was significantly greater in nearly all lakes compared with variance on days with PAR levels above this threshold. The relationship between daily variance in Schmidt stability and GPP model parameter variance depended on trophic status, whereas daily variance in Schmidt stability was consistently positively related to ER model parameter variance. Wind speeds in the range of ~0.8-3 m s–1 were consistent predictors of high variance for both GPP and ER model parameters, with greater uncertainty in eutrophic lakes. Our findings can be used to reduce ecosystem metabolism model parameter uncertainty and identify potential sources of that uncertainty.

  10. Carbon-Flow-Based Modeling of Ecophysiological Processes and Biomass Dynamics of Submersed Aquatic Plants

    Science.gov (United States)

    2007-09-01

    tion”) and emergent flowers (Den Hartog 1982). Typical partitioning of biomass—73.1 percent in leaves, 18.3 percent in stems, and 8.6 percent in...ecosystems. Aquat. Bot. 33: 191-206. Crow, G. E., and C. B. Hellquist. 2000. Aquatic and wetland plants of North America. Vol. 2, p. 36. Den Hartog , C...Aquat. Bot. 22: 33-44. Giesen, W. B. J. T., M. M. Van Katwijk, and C. Den Hartog . 1990. Eelgrass condition and turbidity in the Dutch Wadden Sea

  11. Ecosystem-based management of coastal eutrophication

    DEFF Research Database (Denmark)

    Andersen, Jesper H.

    This thesis focuses on Ecosystem-Based Management (EBM) of coastal eutrophication. Special attention is put on connections between science and decision-making in regard to development, implementation and revision of evidence-based nutrient management strategies. Two strategies are presented...... and analysed: the Danish Action Plans on the Aquatic Environment and the eutrophication segment of the Baltic Sea Action Plan. Similarities and differences are discussed and elements required for making nutrient management strategies successful are suggested. Key words: Eutrophication, marine, Danish...

  12. Early Pleistocene aquatic resource use in the Turkana Basin.

    Science.gov (United States)

    Archer, Will; Braun, David R; Harris, Jack W K; McCoy, Jack T; Richmond, Brian G

    2014-12-01

    Evidence for the acquisition of nutritionally dense food resources by early Pleistocene hominins has implications for both hominin biology and behavior. Aquatic fauna may have comprised a source of highly nutritious resources to hominins in the Turkana Basin at ∼1.95 Ma. Here we employ multiple datasets to examine the issue of aquatic resource use in the early Pleistocene. This study focuses on four components of aquatic faunal assemblages (1) taxonomic diversity, (2) skeletal element proportion, (3) bone fragmentation and (4) bone surface modification. These components are used to identify associations between early Pleistocene aquatic remains and hominin behavior at the site of FwJj20 in the Koobi Fora Fm. (Kenya). We focus on two dominant aquatic species: catfish and turtles. Further we suggest that data on aquatic resource availability as well as ethnographic examples of aquatic resource use complement our observations on the archaeological remains from FwJj20. Aquatic food items provided hominins with a valuable nutritional alternative to an exclusively terrestrial resource base. We argue that specific advantages afforded by an aquatic alternative to terrestrial resources include (1) a probable reduction in required investment of energy relative to economic return in the form of nutritionally dense food items, (2) a decrease in the technological costs of resource acquisition, and (3) a reduced level of inter-specific competition associated with carcass access and an associated reduction of predation risk relative to terrestrial sources of food. The combined evidence from FwJj20 suggests that aquatic resources may have played a substantial role in early Pleistocene diets and these resources may have been overlooked in previous interpretations of hominin behavior.

  13. 园林景观中水生植物的应用分析%Analysis of Aquatic Plants Applied in Landscape Architecture

    Institute of Scientific and Technical Information of China (English)

    杨明艳

    2016-01-01

    The aquatic plant is the essential in making water scene and plays great role in a botanical garden. However, the inte-grated function of aquatic plant usually doesn`t work well for some reasons including improperly use, lack of variety research, form dull, poor management and communication barrier between designer and construction unit. It is then suggested that more aquatic species should be considered and plant them in a rational way, rich aquatic plant configuration, optimize aquatic eco-systems, make the aquatic plants work well to the maximum.%水生植物是园林水景造景的主要素材,在园林植物中具有重要的地位。然而,由于水生植物使用不规范,品种的开发性研究不足,运用形式单调,管理粗放,生态功能发挥不够,设计者与施工单位缺少必要沟通等各种原因,水生植物的综合功能没有得以充分发挥。建议增加水景中水生植物种类,合理栽种水生植物,丰富水生植物的配置方式,优化水景的水生生态系统设计,最大限度发挥水生植物的作用。

  14. Is an ecosystem services-based approach developed for setting specific protection goals for plant protection products applicable to other chemicals?

    Science.gov (United States)

    Maltby, Lorraine; Jackson, Mathew; Whale, Graham; Brown, A Ross; Hamer, Mick; Solga, Andreas; Kabouw, Patrick; Woods, Richard; Marshall, Stuart

    2017-02-15

    Clearly defined protection goals specifying what to protect, where and when, are required for designing scientifically sound risk assessments and effective risk management of chemicals. Environmental protection goals specified in EU legislation are defined in general terms, resulting in uncertainty in how to achieve them. In 2010, the European Food Safety Authority (EFSA) published a framework to identify more specific protection goals based on ecosystem services potentially affected by plant protection products. But how applicable is this framework to chemicals with different emission scenarios and receptor ecosystems? Four case studies used to address this question were: (i) oil refinery waste water exposure in estuarine environments; (ii) oil dispersant exposure in aquatic environments; (iii) down the drain chemicals exposure in a wide range of ecosystems (terrestrial and aquatic); (iv) persistent organic pollutant exposure in remote (pristine) Arctic environments. A four-step process was followed to identify ecosystems and services potentially impacted by chemical emissions and to define specific protection goals. Case studies demonstrated that, in principle, the ecosystem services concept and the EFSA framework can be applied to derive specific protection goals for a broad range of chemical exposure scenarios. By identifying key habitats and ecosystem services of concern, the approach offers the potential for greater spatial and temporal resolution, together with increased environmental relevance, in chemical risk assessments. With modifications including improved clarity on terminology/definitions and further development/refinement of the key concepts, we believe the principles of the EFSA framework could provide a methodical approach to the identification and prioritization of ecosystems, ecosystem services and the service providing units that are most at risk from chemical exposure.

  15. Scenarios for Ecosystem Services: An Overview

    Directory of Open Access Journals (Sweden)

    Elena M. Bennett

    2006-06-01

    Full Text Available The Millennium Ecosystem Assessment (MA scenarios address changes in ecosystem services and their implications for human well-being. Ecological changes pose special challenges for long-term thinking, because of the possibility of regime shifts that occur rapidly yet alter the availability of ecosystem services for generations. Moreover, ecological feedbacks can intensify human modification of ecosystems, creating a spiral of poverty and ecosystem degradation. Such complex dynamics were evaluated by a mixture of qualitative and quantitative analyses in the MA scenarios. Collectively, the scenarios explore problems such as the connections of poverty reduction and ecosystem services, and trade-offs among ecosystem services. Several promising approaches are considered by the scenarios, including uses of biodiversity to build resilience of ecosystem services, actively adaptive management, and green technology. Although the scenarios do not prescribe an optimal path, they illuminate the consequences of different policies toward ecosystem services.

  16. Seagrass ecosystems in the Western Indian Ocean.

    Science.gov (United States)

    Gullström, Martin; de la Torre Castro, Maricela; Bandeira, Salomão; Björk, Mats; Dahlberg, Mattis; Kautsky, Nils; Rönnbäck, Patrik; Ohman, Marcus C

    2002-12-01

    Seagrasses are marine angiosperms widely distributed in both tropical and temperate coastal waters creating one of the most productive aquatic ecosystems on earth. In the Western Indian Ocean (WIO) region, with its 13 reported seagrass species, these ecosystems cover wide areas of near-shore soft bottoms through the 12 000 km coastline. Seagrass beds are found intertidally as well as subtidally, sometimes down to about 40 m, and do often occur in close connection to coral reefs and mangroves. Due to the high primary production and a complex habitat structure, seagrass beds support a variety of benthic, demersal and pelagic organisms. Many fish and shellfish species, including those of commercial interest, are attracted to seagrass habitats for foraging and shelter, especially during their juvenile life stages. Examples of abundant and widespread fish species associated to seagrass beds in the WIO belong to the families Apogonidae, Blenniidae, Centriscidae, Gerreidae, Gobiidae, Labridae, Lethrinidae Lutjanidae, Monacanthidae, Scaridae, Scorpaenidae, Siganidae, Syngnathidae and Teraponidae. Consequently, seagrass ecosystems in the WIO are valuable resources for fisheries at both local and regional scales. Still, seagrass research in the WIO is scarce compared to other regions and it is mainly focusing on botanic diversity and ecology. This article reviews the research status of seagrass beds in the WIO with particular emphasis on fish and fisheries. Most research on this topic has been conducted along the East African coast, i.e. in Kenya, Tanzania, Mozambique and eastern South Africa, while less research was carried out in Somalia and the Island States of the WIO (Seychelles, Comoros, Reunion (France), Mauritius and Madagascar). Published papers on seagrass fish ecology in the region are few and mainly descriptive. Hence, there is a need of more scientific knowledge in the form of describing patterns and processes through both field and experimental work

  17. Ecosystem approach to inland fisheries: research needs and implementation strategies

    Science.gov (United States)

    Beard, T. Douglas; Arlinghaus, Robert; Cooke, Steven J.; McIntyre, Peter B.; De Silva, Sena; Bartley, Devin M.; Cowx, Ian G.

    2011-01-01

    Inland fisheries are a vital component in the livelihoods and food security of people throughout the world, as well as contributing huge recreational and economic benefits. These valuable assets are jeopardized by lack of research-based understanding of the impacts of fisheries on inland ecosystems, and similarly the impact of human activities associated with inland waters on fisheries and aquatic biodiversity. To explore this topic, an international workshop was organized in order to examine strategies to incorporate fisheries into ecosystem approaches for management of inland waters. To achieve this goal, a new research agenda is needed that focuses on: quantifying the ecosystem services provided by fresh waters; quantifying the economic, social and nutritional benefits of inland fisheries; improving assessments designed to evaluate fisheries exploitation potential; and examining feedbacks between fisheries, ecosystem productivity and aquatic biodiversity. Accomplishing these objectives will require merging natural and social science approaches to address coupled social–ecological system dynamics.

  18. Les mammiferes aquatiques: lexique anglais-francais des mammiferes marins actuels ou recemment disparus, y compris les especes d'eau douce des groupes surtout marins (Aquatic Mammals: English-French Glossary of Livinq or Recently Extinct Marine Mammals, Including the Fresh Water Species of Prevalently Marine Groups).

    Science.gov (United States)

    Nekrassoff, Vladimir N.

    1980-01-01

    Introduces a new glossary of aquatic mammals representing recent taxonomic revisions. Describes its design, which consists of the glossary proper, listing the scientific name of each entry followed by its English and French equivalents, and of two indexes, listing other common names for the same entries referred back to the scientific term. (MES)

  19. Oxidative mitigation of aquatic methane emissions in large Amazonian rivers.

    Science.gov (United States)

    Sawakuchi, Henrique O; Bastviken, David; Sawakuchi, André O; Ward, Nicholas D; Borges, Clovis D; Tsai, Siu M; Richey, Jeffrey E; Ballester, Maria Victoria R; Krusche, Alex V

    2016-03-01

    The flux of methane (CH4 ) from inland waters to the atmosphere has a profound impact on global atmospheric greenhouse gas (GHG) levels, and yet, strikingly little is known about the dynamics controlling sources and sinks of CH4 in the aquatic setting. Here, we examine the cycling and flux of CH4 in six large rivers in the Amazon basin, including the Amazon River. Based on stable isotopic mass balances of CH4 , inputs and outputs to the water column were estimated. We determined that ecosystem methane oxidation (MOX) reduced the diffusive flux of CH4 by approximately 28-96% and varied depending on hydrologic regime and general geochemical characteristics of tributaries of the Amazon River. For example, the relative amount of MOX was maximal during high water in black and white water rivers and minimal in clear water rivers during low water. The abundance of genetic markers for methane-oxidizing bacteria (pmoA) was positively correlated with enhanced signals of oxidation, providing independent support for the detected MOX patterns. The results indicate that MOX in large Amazonian rivers can consume from 0.45 to 2.07 Tg CH4 yr(-1) , representing up to 7% of the estimated global soil sink. Nevertheless, climate change and changes in hydrology, for example, due to construction of dams, can alter this balance, influencing CH4 emissions to atmosphere.

  20. Integrating Human and Ecosystem Health Through Ecosystem Services Frameworks.

    Science.gov (United States)

    Ford, Adriana E S; Graham, Hilary; White, Piran C L

    2015-12-01

    The pace and scale of environmental change is undermining the conditions for human health. Yet the environment and human health remain poorly integrated within research, policy and practice. The ecosystem services (ES) approach provides a way of promoting integration via the frameworks used to represent relationships between environment and society in simple visual forms. To assess this potential, we undertook a scoping review of ES frameworks and assessed how each represented seven key dimensions, including ecosystem and human health. Of the 84 ES frameworks identified, the majority did not include human health (62%) or include feedback mechanisms between ecosystems and human health (75%). While ecosystem drivers of human health are included in some ES frameworks, more comprehensive frameworks are required to drive forward research and policy on environmental change and human health.

  1. The effect of radioactive contamination of the Yenisei river on cytogenetic characteristics of aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Bolsunovsky, A.; Medvedeva, M. [Institute of Biophysics SB Russian Academy of Sciences (Russian Federation); Muratova, E. [Institute of Forest SB Russian Academy of Sciences (Russian Federation)

    2014-07-01

    The Yenisei River, one of the world's largest rivers, is contaminated with artificial radionuclides released by one of the Russian facilities producing weapons-grade plutonium (the Mining-and-Chemical Combine, MCC), which has been in operation for many years. Aquatic plants are an important component of water ecosystems, which can accumulate high levels of radionuclides and, thus, can be used in bio-monitoring and bioremediation. The purpose of the study was to assess levels of radionuclides and to evaluate the frequency of chromosomal aberrations in samples of submerged plants collected in different parts of the Yenisei River. The following species were studied: Fontinalis antipyretica, Batrachium kauffmanii, Myriophyllum spicatum, Elodea canadensis, Ceratophyllum demersum and various Potamogeton species. Samples were collected at positions in the vicinity of the MCC discharge point, at a distance of 330 km downstream of Krasnoyarsk, and upstream of the MCC, during sampling campaigns in 2003-2012. Detailed analysis of radioactive contamination of aquatic plants of the Yenisei River revealed large-scale contamination of aquatic plants as far as 250 km downstream of the MCC. Before the last MCC reactor was shut down in 2010, about 30 radionuclides, including uranium and transuranium elements, were detected in the biomass of aquatic plants. The highest concentration factors of the major radionuclides were obtained for Fontinalis antipyretica and Potamogeton lucens. Samples of the plants collected after the shutdown of the reactor contained considerably lower activity levels of artificial radionuclides, and their diversity was significantly decreased. Results of cytogenetic investigations of aquatic plants collected when the reactor was still operating (2003-2009) suggest that at the MCC discharge site and downstream the occurrence of chromosomal aberrations in ana-telophase and metaphase cells of the plants was considerably higher (up to 30%) than in the control

  2. Effect-Based Tools for Monitoring and Predicting the Ecotoxicological Effects of Chemicals in the Aquatic Environment

    Directory of Open Access Journals (Sweden)

    Richard E. Connon

    2012-09-01

    Full Text Available Ecotoxicology faces the challenge of assessing and predicting the effects of an increasing number of chemical stressors on aquatic species and ecosystems. Herein we review currently applied tools in ecological risk assessment, combining information on exposure with expected biological effects or environmental water quality standards; currently applied effect-based tools are presented based on whether exposure occurs in a controlled laboratory environment or in the field. With increasing ecological relevance the reproducibility, specificity and thus suitability for standardisation of methods tends to diminish. We discuss the use of biomarkers in ecotoxicology including ecotoxicogenomics-based endpoints, which are becoming increasingly important for the detection of sublethal effects. Carefully selected sets of biomarkers allow an assessment of exposure to and effects of toxic chemicals, as well as the health status of organisms and, when combined with chemical analysis, identification of toxicant(s. The promising concept of “adverse outcome pathways (AOP” links mechanistic responses on the cellular level with whole organism, population, community and potentially ecosystem effects and services. For most toxic mechanisms, however, practical application of AOPs will require more information and the identification of key links between responses, as well as key indicators, at different levels of biological organization, ecosystem functioning and ecosystem services.

  3. Influence of trophic status on the behaviour of contaminants in aquatic systems

    Science.gov (United States)

    Baxter, R. M.; Carey, J. H.; Lean, D. R. S.; Burnison, B. K.

    1992-01-01

    The problems of eutrophication through nutrient enrichment and contamination with persistent contaminants have traditionally been regarded as unrelated by water scientists and managers, but recently evidence has appeared suggesting that the fate of organic contaminants in an aquatic ecosystem is influenced by the trophic state of the system. There is also evidence that the dissolved organic matter in dystrophic, or humic, waters may influence contaminant dynamics. Mechanisms that may be involved include changes in the metabolic capabilities of organisms with changes in trophic state; reductive degradation in the anoxic hypolimnia of highly productive waters; binding of contaminants by dissolved organic matter or organisms, or photochemical degradation induced by light-absorbing molecules. The possible significance of these processes is discussed.

  4. Aquatic heterotrophic bacteria have highly flexible phosphorus content and biomass stoichiometry.

    Science.gov (United States)

    Godwin, Casey M; Cotner, James B

    2015-10-01

    Bacteria are central to the cycling of carbon (C), nitrogen (N) and phosphorus (P) in every ecosystem, yet our understanding of how tightly these cycles are coupled to bacterial biomass composition is based upon data from only a few species. Bacteria are commonly assumed to have high P content, low biomass C:P and N:P ratios, and inflexible stoichiometry. Here, we show that bacterial assemblages from lakes exhibit unprecedented flexibility in their P content (3% to less than 0.01% of dry mass) and stoichiometry (C:N:P of 28: 7: 1 to more than 8500: 1200: 1). The flexibility in C:P and N:P stoichiometry was greater than any species or assemblage, including terrestrial and aquatic autotrophs, and suggests a highly dynamic role for bacteria in coupling multiple element cycles.

  5. Predicting Watershed Ecosystems Through Targeted Local Land Use Policies

    OpenAIRE

    2006-01-01

    Land-use change is arguably the most pervasive socioeconomic force driving the change and degradation of watershed ecosystems. This paper combines an econometric model of land use choice with three models of watershed health indicators (conventional water pollution, toxic water pollution, and the number of aquatic species at risk) to examine the effects of land use policies on watershed ecosystems through their effect on land use choice. The analysis is conducted using parcel-level data from ...

  6. 关于中国淡水生态系统生物多样性监测与管理的探讨%BIODIVERSITY MONITORING FOR AND MANAGEMENT OF FRESHWATER ECOSYSTEMS IN CHINA: A DISCUSSION AND POSITION PAPER

    Institute of Scientific and Technical Information of China (English)

    XU Dong-Jiong; LI Gang

    2006-01-01

    Due to the rapid economic growth and the continuous increase of human, ecosystem disturbances and habitat destructions, the biodiversity of freshwater ecosystems in China is rapidly declining. This issue is gradually gaining the government's attention as its environmental policy becomes more and more equally-weighed on both "pollution prevention and control" and "ecological conservation" issues while only the former was emphasized in the past. However, some unsolved issues still exist with regard to aquatic biodiversity monitoring and management in China. For example, there are functional overlaps among governmental departments; regional ecological function divisions are not clarified; biodiversity is usually neglected or not emphasized in environmental impact assessment for construction projects; and so on. In our opinion, the following areas should be emphasied: (a) enhancing the cooperation among governmental departments; (b) setting up mechanisms to allow ecological watershed management;(c) establishing the biodiversity conservation and ecological restoration planning for local freshwater ecosystem; (d) clarifying the ecological function divisions; (e) enhancing the biodiversity monitoring and management for freshwater ecosystem in environmental impact assessment studies for industrial construction and rural development projects; (f) establishing a technical regulatory framework for related monitoring and management activities which includes an index system for monitoring and assessment; (g) studying and establishing the related biological criteria for formulating assessment standards; and (h) paying attention to aquatic vegetation,fishes, benthic macro-invertebrates and other key aquatic assemblages.

  7. Assessment of risk to aquatic biota from elevated salinity -- a case study from the Hunter River, Australia.

    Science.gov (United States)

    Muschal, Monika

    2006-05-01

    An ecological risk assessment was performed on salinity levels of the Hunter River and its tributaries to respond to concerns that high salinity may be damaging aquatic ecosystems. Probabilistic techniques were used to assess likelihood and consequence, and hence the risk to aquatic biota from salinity. Continuous electrical conductivity distributions were used to describe the likelihood that high salinity would occur (exposure dataset) and toxicity values were compiled from the limited literature sources available to describe the consequence of high salinity (effects dataset). The assessment was preliminary in the sense that it modelled risk on the basis of existing data and did not undertake site-specific toxicity testing. Some sections of the Hunter River catchment have geologies that are saline because of their marine origins. Catchment development has increased the liberation rates of salts into surface-waters. Such modifying activities include coal-mining, power generation and land clearing. The aquatic biota of tributaries had a greater risk of impairment from high salinity than that of the Hunter River. High salinities in the tributaries were attributed to the combined factors of naturally saline geologies, increased liberation of salts due to modification of the landscape, and reduced dilution by flushing flows. A salinity guideline trigger value of 1100 mg L(-1) was recommended.

  8. Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico

    Directory of Open Access Journals (Sweden)

    Manuel Mendoza-Carranza

    Full Text Available Mangrove and seagrass habitats are important components of tropical coastal zones worldwide, and are conspicuous habitats of Centla Wetland Biosphere Reserve (CWBR in Tabasco, Mexico. In this study, we examine food webs in mangrove- and seagrass-dominated habitats of CWBR using stable isotope ratios of carbon and nitrogen. Our objective was to identify the importance of carbon derived from mangroves and seagrasses to secondary production of aquatic consumers in this poorly studied conservation area. Carbon and nitrogen isotope ratios of basal sources and aquatic consumers indicated that the species-rich food webs of both habitats are dependent on riparian production sources. The abundant Red mangrove Rhizophora mangle appears to be a primary source of carbon for the mangrove creek food web. Even though dense seagrass beds were ubiquitous, most consumers in the lagoon food web appeared to rely on carbon derived from riparian vegetation (e.g. Phragmites australis. The introduced Amazon sailfin catfish Pterygoplichthys pardalis had isotope signatures overlapping with native species (including high-value fisheries species, suggesting potential competition for resources. Future research should examine the role played by terrestrial insects in linking riparian and aquatic food webs, and impacts of the expanding P. pardalis population on ecosystem function and fisheries in CWBR. Our findings can be used as a baseline to reinforce the conservation and management of this important reserve in the face of diverse external and internal human impacts.

  9. Integrated monitoring and information systems for managing aquatic invasive species in a changing climate

    Science.gov (United States)

    Lee, Henry; Reusser, Deborah A.; Olden, Julian D.; Smith, Scott S.; Graham, Jim; Burkett, Virginia; Dukes, Jeffrey S.; Piorkowski, Robert J.; Mcphedran, John

    2008-01-01

    Changes in temperature, precipitation, and other climatic drivers and sea-level rise will affect populations of existing native and non-native aquatic species and the vulnerability of aquatic environments to new invasions. Monitoring surveys provide the foundation for assessing the combined effects of climate change and invasions by providing baseline biotic and environmental conditions, although the utility of a survey depends on whether the results are quantitative or qualitative, and other design considerations. The results from a variety of monitoring programs in the United States are available in integrated biological information systems, although many include only non-native species, not native species. Besides including natives, we suggest these systems could be improved through the development of standardized methods that capture habitat and physiological requirements and link regional and national biological databases into distributed Web portals that allow drawing information from multiple sources. Combining the outputs from these biological information systems with environmental data would allow the development of ecological-niche models that predict the potential distribution or abundance of native and non-native species on the basis of current environmental conditions. Environmental projections from climate models can be used in these niche models to project changes in species distributions or abundances under altered climatic conditions and to identify potential high-risk invaders. There are, however, a number of challenges, such as uncertainties associated with projections from climate and niche models and difficulty in integrating data with different temporal and spatial granularity. Even with these uncertainties, integration of biological and environmental information systems, niche models, and climate projections would improve management of aquatic ecosystems under the dual threats of biotic invasions and climate change

  10. Aquatic exercise in the treatment of children with cerebral palsy

    OpenAIRE

    Dimitrijević Lidija; Bjelaković Bojko; Lazović Milica; Stanković Ivona; Čolović Hristina; Kocić Mirjana; Zlatanović Dragan

    2012-01-01

    Introduction. Aquatic exercise is one of the most popular supplementary treatments for children with neuro-motor impairment, especially for cerebral palsy (CP). As water reduces gravity force which increases postural stability, a child with CP exercises more easily in water than on land. Objective. The aim of the study was to examine aquatic exercise effects on gross motor functioning, muscle tone and cardiorespiratory endurance in children with spastic CP. Methods. The study included 1...

  11. Aquatic Invertebrate Development Working Group

    Science.gov (United States)

    Meyers, D.

    1985-01-01

    Little definitive evidence exists to show that gravity plays a major role in embyrogenesis of aquatic invertebrates. Two reasons for this may be: (1) few studies have been done that emphasize the role of gravity; and (2) there simply may not be any gravity effect. The buoyant nature of the aquatic environment could have obscured any evolutionary effect of gravity. The small size of most eggs and their apparent lack of orientation suggests reduced gravitational influence. Therefore, it is recommended that the term development, as applied to aquatic invertebrates, be loosely defined to encompass behavioral and morphological parameters for which baseline data already exist.

  12. Partitioning ecosystems for sustainability.

    Science.gov (United States)

    Murray, Martyn G

    2016-03-01

    Decline in the abundance of renewable natural resources (RNRs) coupled with increasing demands of an expanding human population will greatly intensify competition for Earth's natural resources during this century, yet curiously, analytical approaches to the management of productive ecosystems (ecological theory of wildlife harvesting, tragedy of the commons, green economics, and bioeconomics) give only peripheral attention to the driving influence of competition on resource exploitation. Here, I apply resource competition theory (RCT) to the exploitation of RNRs and derive four general policies in support of their sustainable and equitable use: (1) regulate resource extraction technology to avoid damage to the resource base; (2) increase efficiency of resource use and reduce waste at every step in the resource supply chain and distribution network; (3) partition ecosystems with the harvesting niche as the basic organizing principle for sustainable management of natural resources by multiple users; and (4) increase negative feedback between consumer and resource to bring about long-term sustainable use. A simple policy framework demonstrates how RCT integrates with other elements of sustainability science to better manage productive ecosystems. Several problem areas of RNR management are discussed in the light of RCT, including tragedy of the commons, overharvesting, resource collapse, bycatch, single species quotas, and simplification of ecosystems.

  13. Biocomplexity in Mangrove Ecosystems

    Science.gov (United States)

    Feller, I. C.; Lovelock, C. E.; Berger, U.; McKee, K. L.; Joye, S. B.; Ball, M. C.

    2010-01-01

    Mangroves are an ecological assemblage of trees and shrubs adapted to grow in intertidal environments along tropical coasts. Despite repeated demonstration of their economic and societal value, more than 50% of the world's mangroves have been destroyed, 35% in the past two decades to aquaculture and coastal development, altered hydrology, sea-level rise, and nutrient overenrichment. Variations in the structure and function of mangrove ecosystems have generally been described solely on the basis of a hierarchical classification of the physical characteristics of the intertidal environment, including climate, geomorphology, topography, and hydrology. Here, we use the concept of emergent properties at multiple levels within a hierarchical framework to review how the interplay between specialized adaptations and extreme trait plasticity that characterizes mangroves and intertidal environments gives rise to the biocomplexity that distinguishes mangrove ecosystems. The traits that allow mangroves to tolerate variable salinity, flooding, and nutrient availability influence ecosystem processes and ultimately the services they provide. We conclude that an integrated research strategy using emergent properties in empirical and theoretical studies provides a holistic approach for understanding and managing mangrove ecosystems.

  14. Ecosystem engineering effects on species diversity across ecosystems: a meta-analysis.

    Science.gov (United States)

    Romero, Gustavo Q; Gonçalves-Souza, Thiago; Vieira, Camila; Koricheva, Julia

    2015-08-01

    Ecosystem engineering is increasingly recognized as a relevant ecological driver of diversity and community composition. Although engineering impacts on the biota can vary from negative to positive, and from trivial to enormous, patterns and causes of variation in the magnitude of engineering effects across ecosystems and engineer types remain largely unknown. To elucidate the above patterns, we conducted a meta-analysis of 122 studies which explored effects of animal ecosystem engineers on species richness of other organisms in the community. The analysis revealed that the overall effect of ecosystem engineers on diversity is positive and corresponds to a 25% increase in species richness, indicating that ecosystem engineering is a facilitative process globally. Engineering effects were stronger in the tropics than at higher latitudes, likely because new or modified habitats provided by engineers in the tropics may help minimize competition and predation pressures on resident species. Within aquatic environments, engineering impacts were stronger in marine ecosystems (rocky shores) than in streams. In terrestrial ecosystems, engineers displayed stronger positive effects in arid environments (e.g. deserts). Ecosystem engineers that create new habitats or microhabitats had stronger effects than those that modify habitats or cause bioturbation. Invertebrate engineers and those with lower engineering persistence (1 year. Invertebrate species richness was particularly responsive to engineering impacts. This study is the first attempt to build an integrative framework of engineering effects on species diversity; it highlights the importance of considering latitude, habitat, engineering functional group, taxon and persistence of their effects in future theoretical and empirical studies.

  15. Food-web composition affects cross-ecosystem interactions and subsidies.

    Science.gov (United States)

    Romero, Gustavo Q; Srivastava, Diane S

    2010-09-01

    1. Ecosystems may affect each other through trophic interactions that cross ecosystem boundaries as well as via the transfer of subsidies, but these effects can vary depending on the identity of species involved in the interaction. 2. In this study, we manipulated two terrestrial bromeliad-living spider species (Aglaoctenus castaneus, Corinna gr. rubripes) that have variable hunting modes, to test their individual and combined effects on aquatic invertebrate community structure and ecosystem processes (i.e. decomposition rate and nitrogen cycling). We predicted that these terrestrial predators can affect aquatic invertebrates and nutrient dynamics within water-filled bromeliads. 3. Aglaoctenus spiders reduced the richness, abundance and biomass of aquatic insect larvae via consumptive or non-consumptive effects on ovipositing terrestrial adults, but effects of the two spider species in combination were usually the linear average of their monoculture effects. In contrast, invertebrates with entirely aquatic life cycles were unaffected or facilitated by spiders. Spiders did not affect either net detritivore biomass or the flux of detrital nitrogen to the bromeliad. Instead, Corinna spiders contributed allochthonous nitrogen to bromeliads. 4. Our results provide the novel observations that predators in one ecosystem not only directly reduce taxa whose life cycles cross-ecosystem boundaries, but also indirectly facilitate taxa whose life cycles are entirely within the second ecosystem. This compensatory response between cross-ecosystem and within-ecosystem taxa may have led to an attenuation of top-down effects across ecosystem boundaries. In addition, our results add to a growing consensus that species identity is an important determinant of community structure and ecosystem functioning. Thus, the composition of both terrestrial and aquatic food webs may affect the strength of cross-ecosystem interactions.

  16. [Measuring water ecological carrying capacity with the ecosystem-service-based ecological footprint (ESEF) method: Theory, models and application].

    Science.gov (United States)

    Jiao, Wen-jun; Min, Qing-wen; Li, Wen-hua; Fuller, Anthony M

    2015-04-01

    Integrated watershed management based on aquatic ecosystems has been increasingly acknowledged. Such a change in the philosophy of water environment management requires recognizing the carrying capacity of aquatic ecosystems for human society from a more general perspective. The concept of the water ecological carrying capacity is therefore put forward, which considers both water resources and water environment, connects socio-economic development to aquatic ecosystems and provides strong support for integrated watershed management. In this paper, the authors proposed an ESEF-based measure of water ecological carrying capacity and constructed ESEF-based models of water ecological footprint and capacity, aiming to evaluate water ecological carrying capacity with footprint methods. A regional model of Taihu Lake Basin was constructed and applied to evaluate the water ecological carrying capacity in Changzhou City which located in the upper reaches of the basin. Results showed that human demand for water ecosystem services in this city had exceeded the supply capacity of local aquatic ecosystems and the significant gap between demand and supply had jeopardized the sustainability of local aquatic ecosystems. Considering aqua-product provision, water supply and pollutant absorption in an integrated way, the scale of population and economy aquatic ecosystems in Changzhou could bear only 54% of the current status.

  17. Integrated modelling for assessing the risk of groundwater contaminants to human health and surface water ecosystems

    DEFF Research Database (Denmark)

    McKnight, Ursula S.; Rasmussen, Jes; Funder, Simon G.;

    2010-01-01

    for evaluating the impact of a TCE groundwater plume, located in an area with protected drinking water interests, to human health and surface water ecosystems. This is accomplished by coupling the system dynamicsbased decision support system CARO-Plus to the aquatic ecosystem model AQUATOX via an analytical...

  18. Columbia Estuary Ecosystem Restoration Program. 2012 Synthesis Memorandum

    Science.gov (United States)

    2013-01-01

    1 CEERP is an acronym coined in 2011 for the joint BPA/Corps efforts to restore LCRE ecosystems that...Baross, and CA Simenstad. 1998. “Dominance of particle–attached bacteria in the Columbia River estuary, USA.” Aquatic Microbial Ecology 14:7-18. 9.4

  19. Tunison Laboratory of Aquatic Science

    Data.gov (United States)

    Federal Laboratory Consortium — Tunison Laboratory of Aquatic Science (TLAS), located in Cortland, New York, is a field station of the USGS Great Lakes Science Center (GLSC). TLAS was established...

  20. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    Many terrestrial plant canopies regulate spatial patterns in leaf density and leaf inclination to distribute light evenly between the photosynthetic tissue and to optimize light utilization efficiency. Sessile aquatic macrophytes, however, cannot maintain the same well-defined three......-dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...... was markedly enhanced by a vertical orientation of thalli when absorptance and community density were both high. This result implies that aquatic macrophytes of high thallus absorptance and community density exposed to high light are limited in attaining high gross production rates because of their inability...

  1. Forty years of experiments on aquatic invasive species: are study biases limiting our understanding of impacts?

    Directory of Open Access Journals (Sweden)

    Mads Thomsen

    2014-06-01

    Full Text Available Invasions by non-native species are a threat to biodiversity because invaders can impact native populations, communities and entire ecosystems. To manage this threat, it is necessary to have a strong mechanistic understanding of how non-native species affect local species and communities. We reviewed 259 published papers (1972–2012 that described field experiments quantifying the impact of aquatic non-native species, to examine whether various types of study biases are limiting this understanding. Our review revealed that invasion impacts had been experimentally quantified for 101 aquatic non-native species, in all major freshwater and marine habitats, on all continents except Antarctica and for most higher taxonomic groupings. Over one-quarter (26% of studies included tests for impacts on local biodiversity. However, despite this extensive research effort, certain taxa, habitats and regions remain poorly studied. For example, of the over one hundred species examined in previous studies, only one was a marine fish and only six were herbivores. Furthermore, over half (53% the studies were from the USA and two-thirds (66% were from experiments conducted in temperate latitudes. By contrast, only 3% of studies were from Africa and <2% from high latitudes. We also found that one-fifth (20% of studies were conducted in estuaries, but only 1% from coral reefs. Finally, we note that the standard procedure of pooling or not reporting non-significant treatments and responses is likely to limit future synthetic advancement by biasing meta-analysis and severely limiting our ability to identify non-native species with none or negligible ecological impacts. In conclusion, a future focus on poorly-studied taxa, habitats and regions, and enhanced reporting of results, should improve our understanding and management of impacts associated with aquatic non-native species.

  2. Aquatic Plants Aid Sewage Filter

    Science.gov (United States)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  3. Oligochaeta (Annelida: Clitellata associated to aquatic macrophytes in Brazil

    Directory of Open Access Journals (Sweden)

    Nathalie Aparecida de Oliveira Sanches

    2016-09-01

    Full Text Available Oligochaeta are still characterized as a poorly studied group among the aquatic macroinvertebrates and few studies about their ecology were conducted in Brazil. Thus, our study aimed to provide an overview of the association between Oligochaeta and macrophytes, in Brazilian continental aquatic environments, by means of a literature review along with an inventory of species associated to aquatic macrophytes on marginal lagoons in the reservoir Ribeirão das Anhumas (Américo Brasiliense, São Paulo, Brazil. In the review, we analyzed 10 articles, where we obtained data on 41 species. We also sampled 5 macrophyte genera, Egeria, Salvinia, Utricularia, Eleocharis, and Ceratophyllum, in August and December 2012 and in March and April 2013, in the reservoir Ribeirão das Anhumas. We registered 21 Oligochaeta species associated to these macrophytes. With the data obtained in the review along with the inventory of the reservoir Ribeirão das Anhumas, we found a total of 41 species associated to aquatic macrophytes, with a higher richness of the Naididae family (93.33%, followed by Opistocystidae (4.44%, and Alluroididae (2.22%. Our study inventoried about 48% of the Oligochaeta diversity registered in continental ecosystems in Brazil, thus highlighting the significance of macrophytes as a resource for these invertebrates, mainly for the Naididae family.

  4. Future directions of ecosystem science

    Science.gov (United States)

    Baron, Jill; Galvin, Kathleen A.

    1990-01-01

    Scientific knowledge about ecosystem structure and function has expanded greatly during the past few decades. Terrestrial and aquatic nutrient cycling, ecosystem energetics, population dynamics, belowground processes, and food webs have been studied at the plot, stand, watershed, and landscape levels at many locations around the globe. Ideas about terrestrial-atmospheric interactions and human interference in these processes have changed dramatically. There is new appreciation of the need to incorporate into ecosystem studies the interactions between human populations and the ecosystem, not only because humans affect ecosystem processes, but because these systems support human populations (Glantz 1988, Holden 1988, Parry et al. 1988, WCED 1987). Recent advances in ecosystem science are due, in part, to technological improvements in computing power, new laboratory and field physical and chemical analytical techniques, and satellite imagery for remote sensing of Earth's structure and dynamics. Modeling and geographic information systems have provided the capability for integrating multiple data sets with process simulations to generate hypotheses about regional ecosystem function. Concurrent with these scientific developments has been a growing concern about the links between the health of the environment and world-wide industrial, land, and resource-management practices. Environmental damage at the local level was widely recognized in the 1960s, prompting the environmental movement of that decade. Regional environmental problems with multiple effects and politically difficult solutions have been perceived more recently; the issue of acidic deposition provides an example of such a second-generation concern (Clark and Holling 1985). Today there is a growing awareness of global-scale environmental degradation brought about by the combined actions of all peoples on Earth (Clark 1989, Woodmansee et al. 1988). The three levels of environmental concern--local, regional

  5. Microbial Ecosystems, Protection of

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Conservation of microbial diversity and ecosystem functions provided by microbes; Preservation of microbial diversity and ecosystem functions provided by microbes Definition The use, management, and conservation of ecosystems in order to preserve microbial diversity and functioning. Introdu

  6. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  7. Young mangrove stands produce a large and high quality litter input to aquatic systems

    NARCIS (Netherlands)

    Nga, B.T.; Tinh, H.Q.; Tam, D.T.; Scheffer, M.; Roijackers, R.M.M.

    2005-01-01

    Mangrove swamps are key ecosystems along the Vietnam coast. Although mangrove litter is thought to represent an important input of organic matter and nutrients to the coastal aquatic systems, the factors determining the quality and size of this litter flux have not been studied so far. We monitored

  8. Astronomical Ecosystems

    Science.gov (United States)

    Neuenschwander, D. E.; Finkenbinder, L. R.

    2004-05-01

    Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

  9. Dietary supplements for aquatic sports.

    Science.gov (United States)

    Derave, Wim; Tipton, Kevin D

    2014-08-01

    Many athletes use dietary supplements, with use more prevalent among those competing at the highest level. Supplements are often self-prescribed, and their use is likely to be based on an inadequate understanding of the issues at stake. Supplementation with essential micronutrients may be useful when a diagnosed deficiency cannot be promptly and effectively corrected with food-based dietary solutions. When used in high doses, some supplements may do more harm than good: Iron supplementation, for example, is potentially harmful. There is good evidence from laboratory studies and some evidence from field studies to support health or performance benefits from appropriate use of a few supplements. The available evidence from studies of aquatic sports is small and is often contradictory. Evidence from elite performers is almost entirely absent, but some athletes may benefit from informed use of creatine, caffeine, and buffering agents. Poor quality assurance in some parts of the dietary supplements industry raises concerns about the safety of some products. Some do not contain the active ingredients listed on the label, and some contain toxic substances, including prescription drugs, that can cause health problems. Some supplements contain compounds that will cause an athlete to fail a doping test. Supplement quality assurance programs can reduce, but not entirely eliminate, this risk.

  10. Managing Forests for Water in the Anthropocene—The Best Kept Secret Services of Forest Ecosystems

    Directory of Open Access Journals (Sweden)

    Irena F. Creed

    2016-03-01

    Full Text Available Water and forests are inextricably linked. Pressures on forests from population growth and climate change are increasing risks to forests and their aquatic ecosystem services (AES. There is a need to incorporate AES in forest management but there is considerable uncertainty about how to do so. Approaches that manage forest ecosystem services such as fiber, water and carbon sequestration independently ignore the inherent complexities of ecosystem services and their responses to management actions, with the potential for unintended consequences that are difficult to predict. The ISO 31000 Risk Management Standard is a standardized framework to assess risks to forest AES and to prioritize management strategies to manage risks within tolerable ranges. The framework consists of five steps: establishing the management context, identifying, analyzing, evaluating and treating the risks. Challenges to implementing the framework include the need for novel models and indicators to assess forest change and resilience, quantification of linkages between forest practice and AES, and the need for an integrated systems approach to assess cumulative effects and stressors on forest ecosystems and AES. In the face of recent international agreements to protect forests, there are emerging opportunities for international leadership to address these challenges in order to protect both forests and AES.

  11. Bioaccumulation in aquatic systems: methodological approaches, monitoring and assessment

    DEFF Research Database (Denmark)

    Schäfer, Sabine; Buchmeier, Georgia; Claus, Evelyn;

    2015-01-01

    Bioaccumulation, the accumulation of a chemical in an organism relative to its level in the ambient medium, is of major environmental concern. Thus, monitoring chemical concentrations in biota are widely and increasingly used for assessing the chemical status of aquatic ecosystems. In this paper......, various scientific and regulatory aspects of bioaccumulation in aquatic systems and the relevant critical issues are discussed. Monitoring chemical concentrations in biota can be used for compliance checking with regulatory directives, for identification of chemical sources or event-related environmental...... risk assessment. Assessing bioaccumulation in the field is challenging since many factors have to be considered that can affect the accumulation of a chemical in an organism. Passive sampling can complement biota monitoring since samplers with standardised partition properties can be used over a wide...

  12. Implementation of Traditional and Real-World Cooperative Learning Techniques in Quantitative Analysis Including Near Infrared Spectroscopy for Analysis of Live Fish

    Science.gov (United States)

    Houghton, Tracy P.; Kalivas, John H.

    2000-10-01

    It is important for a modern quantitative analysis laboratory course to contain gravimetric and volumetric analysis exercises implemented with standard unknowns. By analyzing unknowns, students learn crucial laboratory skills. It is also advantageous to introduce real-world samples and cooperative learning structure into the lab course. A one-semester sophomore course at Idaho State University is divided into two parts: students individually perform traditional unknown analyses, and as groups, they study an aquatic ecosystem simulated by a trout aquarium. Ecosystem analyses include the important chemical components of the nitrogen cycle, dissolved oxygen, and alkalinity. In addition to examining the aquatic system, trout are removed temporarily from the aquarium for analysis of lipid and moisture content using near infrared (NIR) spectroscopy. For the ecosystem investigation, students also determine costs of analyses and conduct quality-control studies. At the completion of the course, students are well versed in classical methods of analysis as well as educated on the relevance of modern technology, including up-to-date instrumentation and sophisticated multivariate calibration and prediction procedures. Course assessment results are summarized in the paper.

  13. Assessing the role of large herbivores in the structuring and functioning of freshwater and marine angiosperm ecosystems

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Pagès, Jordi F.; Arthur, Rohan; Alcoverro, Teresa

    2016-01-01

    While large herbivores can have strong impacts on terrestrial ecosystems, much less is known of their role in aquatic systems. We reviewed the literature to determine: (1) which large herbivores (>10 kg) have a (semi-)aquatic lifestyle and are important consumers of submerged vascular plants, (2) th

  14. Food-web composition affects cross-ecosystem interactions and subsidies

    OpenAIRE

    2010-01-01

    P>1. Ecosystems may affect each other through trophic interactions that cross ecosystem boundaries as well as via the transfer of subsidies, but these effects can vary depending on the identity of species involved in the interaction.2. In this study, we manipulated two terrestrial bromeliad-living spider species (Aglaoctenus castaneus, Corinna gr. rubripes) that have variable hunting modes, to test their individual and combined effects on aquatic invertebrate community structure and ecosystem...

  15. Late cretaceous aquatic plant world in Patagonia, Argentina.

    Science.gov (United States)

    Cúneo, N Rubén; Gandolfo, María A; Zamaloa, María C; Hermsen, Elizabeth

    2014-01-01

    In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla) and a monocot (Araceae). Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae). Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form) and the eudicot angiosperm Nelumbo (Nelumbonaceae) are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae), ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

  16. Late cretaceous aquatic plant world in Patagonia, Argentina.

    Directory of Open Access Journals (Sweden)

    N Rubén Cúneo

    Full Text Available In this contribution, we describe latest Cretaceous aquatic plant communities from the La Colonia Formation, Patagonia, Argentina, based on their taxonomic components and paleoecological attributes. The La Colonia Formation is a geological unit deposited during a Maastrichtian-Danian transgressive episode of the South Atlantic Ocean. This event resulted in the deposition of a series of fine-grained sediments associated with lagoon systems occurring along irregular coastal plains in northern Patagonia. These deposits preserved a diverse biota, including aquatic and terrestrial plants and animals. The aquatic macrophytes can be broadly divided into two groups: free-floating and rooted, the latter with emergent or floating leaves. Free-floating macrophytes include ferns in Salviniaceae (Azolla and Paleoazolla and a monocot (Araceae. Floating microphytes include green algae (Botryoccocus, Pediastrum and Zygnemataceae. Among the rooted components, marsileaceous water ferns (including Regnellidium and an extinct form and the eudicot angiosperm Nelumbo (Nelumbonaceae are the dominant groups. Terrestrial plants occurring in the vegetation surrounding the lagoons include monocots (palms and Typhaceae, ferns with affinities to Dicksoniaceae, conifers, and dicots. A reconstruction of the aquatic plant paleocommuniy is provided based on the distribution of the fossils along a freshwater horizon within the La Colonia Formation. This contribution constitutes the first reconstruction of a Cretaceous aquatic habitat for southern South America.

  17. Assessment of the consequences of the radioactive contamination of aquatic media and biota. Model testing using Chernobyl data

    Energy Technology Data Exchange (ETDEWEB)

    Kryshev, I.; Sazykina, T. [SPA Typhoon, Obninsk (Russian Federation); Hoffman, O.; Thiessen, K. [SENES, Oak Ridge, TN (United States)] [and others

    1996-09-01

    The 'Cooling Pond' scenario was designed to test models for radioactive contamination of aquatic ecosystems, based on data for contamination of different aquatic media and biota due to fallout of radionuclides into the cooling pond of the Chernobyl Nuclear Power Plant. Input data included characteristics of the cooling pond ecosystem (hydrological, hydrochemical, and hydro biological conditions) and estimates of the amounts of 137 Cs in the cooling pond. Predictions were requested in two stages: (1) Calculations of 137 Cs concentrations for comparison against actual measurements, including activities of 137 Cs in the cooling pond water, in layers of sediment, and in fish; (2) Calculations for which actual measurements are not available, including dose and risk estimates for aquatic biota and for humans following hypothetical consumption of contaminated biota. Calculations were performed with the following models: LAKECO (Netherlands), POSOD (USA), LAKEPOND (Romania), WATER (Russia), GIDRO (Russia), and ECOMOD-W (Russia). The total number of scenario calculations was 18. In general, the models tended to overestimate the total doses to fish (as compared to to independent dose estimates made from measured concentrations by the scenario authors) for internal and external exposure, while a number of predictions with different models for the effective dose and risk to humans from fish consumption were in good agreement with independent test estimates. The differences among model predictions were somewhat smaller for the total doses to fish than for the environmental concentrations used in the model testing. The differences among model predictions were very great for the effective doses and risk to humans from fish consumption. This is related to distinct errors in assessments of 137 Cs concentrations in fish. Very few participants obtained good agreement with respect to all criteria of the model testing, i.e., 137 Cs concentrations in the aquatic ecosystem

  18. Ecosystem service valuations of mangrove ecosystems to inform decision making and future valuation exercises.

    Science.gov (United States)

    Mukherjee, Nibedita; Sutherland, William J; Dicks, Lynn; Hugé, Jean; Koedam, Nico; Dahdouh-Guebas, Farid

    2014-01-01

    The valuation of ecosystem services is a complex process as it includes several dimensions (ecological, socio-cultural and economic) and not all of these can be quantified in monetary units. The aim of this paper is to conduct an ecosystem services valuation study for mangroves ecosystems, the results of which can be used to inform governance and management of mangroves. We used an expert-based participatory approach (the Delphi technique) to identify, categorize and rank the various ecosystem services provided by mangrove ecosystems at a global scale. Subsequently we looked for evidence in the existing ecosystem services literature for monetary valuations of these ecosystem service categories throughout the biogeographic distribution of mangroves. We then compared the relative ranking of ecosystem service categories between the monetary valuations and the expert based analysis. The experts identified 16 ecosystem service categories, six of which are not adequately represented in the literature. There was no significant correlation between the expert based valuation (the Delphi technique) and the economic valuation, indicating that the scope of valuation of ecosystem services needs to be broadened. Acknowledging this diversity in different valuation approaches, and developing methodological frameworks that foster the pluralism of values in ecosystem services research, are crucial for maintaining the credibility of ecosystem services valuation. To conclude, we use the findings of our dual approach to valuation to make recommendations on how to assess and manage the ecosystem services provided by mangrove ecosystems.

  19. Ecosystem service valuations of mangrove ecosystems to inform decision making and future valuation exercises.

    Directory of Open Access Journals (Sweden)

    Nibedita Mukherjee

    Full Text Available The valuation of ecosystem services is a complex process as it includes several dimensions (ecological, socio-cultural and economic and not all of these can be quantified in monetary units. The aim of this paper is to conduct an ecosystem services valuation study for mangroves ecosystems, the results of which can be used to inform governance and management of mangroves. We used an expert-based participatory approach (the Delphi technique to identify, categorize and rank the various ecosystem services provided by mangrove ecosystems at a global scale. Subsequently we looked for evidence in the existing ecosystem services literature for monetary valuations of these ecosystem service categories throughout the biogeographic distribution of mangroves. We then compared the relative ranking of ecosystem service categories between the monetary valuations and the expert based analysis. The experts identified 16 ecosystem service categories, six of which are not adequately represented in the literature. There was no significant correlation between the expert based valuation (the Delphi technique and the economic valuation, indicating that the scope of valuation of ecosystem services needs to be broadened. Acknowledging this diversity in different valuation approaches, and developing methodological frameworks that foster the pluralism of values in ecosystem services research, are crucial for maintaining the credibility of ecosystem services valuation. To conclude, we use the findings of our dual approach to valuation to make recommendations on how to assess and manage the ecosystem services provided by mangrove ecosystems.

  20. Recreational impacts on the fauna of Australian coastal marine ecosystems.

    Science.gov (United States)

    Hardiman, Nigel; Burgin, Shelley

    2010-11-01

    This paper reviews recent research into the ecological impacts of recreation and tourism on coastal marine fauna in Australia. Despite the high and growing importance of water-based recreation to the Australian economy, and the known fragility of many Australian ecosystems, there has been relatively limited research into the effects of marine tourism and recreation, infrastructure and activities, on aquatic resources. In this paper we have reviewed the ecological impacts on fauna that are caused by outdoor recreation (including tourism) in Australian coastal marine ecosystems. We predict that the single most potentially severe impact of recreation may be the introduction and/or dispersal of non-indigenous species of marine organisms by recreational vessels. Such introductions, together with other impacts due to human activities have the potential to increasingly degrade recreation destinations. In response, governments have introduced a wide range of legislative tools (e.g., impact assessment, protected area reservation) to manage the recreational industry. It would appear, however, that these instruments are not always appropriately applied.

  1. Dynamic phosphorus budget for lake-watershed ecosystems

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; GUO Huai-cheng; WANG Li-jing; DAI Yong-li; ZHANG Xiu-min; LI Zi-hai; HE Bin

    2006-01-01

    Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis(MFA) and system dynamic(SD), is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper.From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27%respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed.

  2. Animal protein production modules in biological life support systems: Novel combined aquaculture techniques based on the closed equilibrated biological aquatic system (C.E.B.A.S.)

    Science.gov (United States)

    Blüm, V.; Andriske, M.; Kreuzberg, K.; Schreibman, M. P.

    Based on the experiences made with the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) which was primarily deveoloped for long-term and multi-generation experiments with aquatic animals and plants in a space station highly effective fresh water recycling modules were elaborated utilizing a combination of ammonia oxidizing bacteria filters and higher plants. These exhibit a high effectivity to eliminate phosphate and anorganic nitrogen compounds and arc. in addidition. able to contribute to the oxygen supply of the aquatic animals. The C.E.B.A.S. filter system is able to keep a closed artificial aquatic ecosystem containing teleost fishes and water snails biologically stable for several month and to eliminate waste products deriving from degraded dead fishes without a decrease of the oxygen concentration down to less than 3.5 mg/l at 25 °C. More advanced C.E.B.A.S. filter systems, the BIOCURE filters, were also developed for utilization in semiintensive and intensive aquaculture systems for fishes. In fact such combined animal-plant aquaculture systems represent highly effective productions sites for human food if proper plant and fish species are selected The present papers elucidates ways to novel aquaculture systems in which herbivorous fishes are raised by feeding them with plant biomass produced in the BIOCURE filters and presents the scheme of a modification which utilizes a plant species suitable also for human nutrition. Special attention is paid to the benefits of closed aquaculture system modules which may be integrated into bioregenerative life support systems of a higher complexity for, e. g.. lunar or planetary bases including some psychologiccal aspects of the introduction of animal protein production into plant-based life support systems. Moreover, the basic reproductive biological problems of aquatic animal breeding under reduced gravity are explained leading to a disposition of essential research programs in this context.

  3. Recent changes in aquatic biota in subarctic Fennoscandia - the role of global and local environmental variables

    Science.gov (United States)

    Weckström, Jan; Leppänen, Jaakko; Sorvari, Sanna; Kaukolehto, Marjut; Weckström, Kaarina; Korhola, Atte

    2013-04-01

    The Arctic, representing a fifth of the earth's surface, is highly sensitive to the predicted future warming and it has indeed been warming up faster than most other regions. This makes the region critically important and highlights the need to investigate the earliest signals of global warming and its impacts on the arctic and subarctic aquatic ecosystems and their biota. It has been demonstrated that many Arctic freshwater ecosystems have already experienced dramatic and unpreceded regime shifts during the last ca. 150 years, primarily driven by climate warming. However, despite the indisputable impact of climate-related variables on freshwater ecosystems other, especially local-scale catchment related variables (e.g. geology, vegetation, human activities) may override the climate signal and become the primary factor in shaping the structure of aquatic ecosystems. Although many studies have contributed to an improved understanding of limnological and hydrobiological features of Artic and subarctic lakes, much information is still needed especially on the interaction between the biotic and abiotic components, i.e. on factors controlling the food web dynamics in these sensitive aquatic ecosystems. This is of special importance as these lakes are of great value in water storage, flood prevention, and maintenance of biodiversity, in addition to which they are vital resources for settlement patterns, food production, recreation, and tourism. In this study we compare the pre-industrial sediment assemblages of primary producers (diatoms and Pediastrum) and primary consumers (cladoceran and chironomids) with their modern assemblages (a top-bottom approach) from 50 subarctic Fennoscandian lakes. We will evaluate the recent regional pattern of changes in aquatic assemblages, and assess how coherent the lakes' responses are across the subarctic area. Moreover, the impact of global (e.g. climate, precipitation) and local (e.g. lake and its catchment characteristics) scale

  4. Temporal scales, ecosystem dynamics, stakeholders and the valuation of ecosystems services

    NARCIS (Netherlands)

    Hein, Lars; Koppen, van C.S.A.K.; Ierland, van Ekko C.; Leidekker, Jakob

    2016-01-01

    Temporal dimensions are highly relevant to the analysis of ecosystem services and their economic value. In this paper, we provide a framework that can be used for analyzing temporal dimensions of ecosystem services, we present a case study including an analysis of the supply of three ecosystem se

  5. Spatial distribution of aquatic insects

    DEFF Research Database (Denmark)

    Iversen, Lars Lønsmann

    Species associated with freshwater ecosystems are currently undergoing severe global declines and freshwater ecosystems are regarded as some of the most endangered ecosystems in the world. These declines are a consequence of decades of human overexploitation, pollution and climate change. If adeq......Species associated with freshwater ecosystems are currently undergoing severe global declines and freshwater ecosystems are regarded as some of the most endangered ecosystems in the world. These declines are a consequence of decades of human overexploitation, pollution and climate change....... Chapters II exemplifies that national changes in land use can influence the perception of a species’ realized niche across different landscapes. By observing the environmental niche of a threatened European dragonfly in landscapes with different land use history it is shown that if a species’ realized...

  6. Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir

    OpenAIRE

    M. B. Cunha-Santino; Fushita,A. T.; PERET, A.C.; Bianchini-Junior,I.

    2016-01-01

    Abstract Macrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g., hydrodynamic and wind exposure) rather than trophic status and depth of the euphotic zone. In this context, this study aimed at desc...

  7. Tritium in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

    1986-02-01

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products.

  8. Aquatic plants for removal of mevinphos from the aquatic environment

    Science.gov (United States)

    Wolverton, B. C.

    1975-01-01

    Fragrant waterlily (Nymphaea odorata, Ait.), joint-grass (Paspalum distichum L.), and rush (Juncus repens, Michx.) were used to evaluate the effectiveness of vascular aquatic plants in removing the insecticide mevinphos (dimethyl-1-carbomethoxy-1propen-2-yl phosphate) from waters contaminated with this chemical. The emersed aquatic plants fragrant waterlily and joint-grass removed 87 and 93 ppm of mevinphos from water test systems in less than 2 weeks without apparent damage to the plants; whereas rush, a submersed plant, removed less insecticide than the water-soil controls. Water-soil control still contained toxic levels of this insecticide, as demonstrated by fish bioassay studies, after 35 days.

  9. Diversity and Distribution of Aquatic Fungal Communities in the Ny-Ålesund Region, Svalbard (High Arctic): Aquatic Fungi in the Arctic.

    Science.gov (United States)

    Zhang, Tao; Wang, Neng-Fei; Zhang, Yu-Qin; Liu, Hong-Yu; Yu, Li-Yan

    2016-04-01

    We assessed the diversity and distribution of fungi in 13 water samples collected from four aquatic environments (stream, pond, melting ice water, and estuary) in the Ny-Ålesund Region, Svalbard (High Arctic) using 454 pyrosequencing with fungi-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Aquatic fungal communities in this region showed high diversity, with a total of 43,061 reads belonging to 641 operational taxonomic units (OTUs) being found. Of these OTUs, 200 belonged to Ascomycota, 196 to Chytridiomycota, 120 to Basidiomycota, 13 to Glomeromycota, and 10 to early diverging fungal lineages (traditional Zygomycota), whereas 102 belonged to unknown fungi. The major orders were Helotiales, Eurotiales, and Pleosporales in Ascomycota; Chytridiales and Rhizophydiales in Chytridiomycota; and Leucosporidiales and Sporidiobolales in Basidiomycota. The common fungal genera Penicillium, Rhodotorula, Epicoccum, Glaciozyma, Holtermanniella, Betamyces, and Phoma were identified. Interestingly, the four aquatic environments in this region harbored different aquatic fungal communities. Salinity, conductivity, and temperature were important factors in determining the aquatic fungal diversity and community composition. The results suggest the presence of diverse fungal communities and a considerable number of potentially novel fungal species in Arctic aquatic environments, which can provide reliable data for studying the ecological and evolutionary responses of fungi to climate change in the Arctic ecosystem.

  10. Remote sensing of aquatic plants. [New York, Florida, Texas, Louisiana, Mississippi, South Carolina

    Science.gov (United States)

    Long, K. S.; Link, L. E., Jr.

    1977-01-01

    Various sensors were tested in terms of their ability to detect and discriminate among noxious aquatic macrophytes. A survey of researchers currently studying the problem and a brief summary of their work is included. Results indicated that the sensor types best suited to assessment of the aquatic environment are color, color infrared, and black-and-white infrared film, which furnish consistently high contrasts between aquatic plants and their surroundings.

  11. Assessment of pollution with aquatic bryophytes in Maritsa River (Bulgaria).

    Science.gov (United States)

    Gecheva, Gana; Yurukova, Lilyana; Ganeva, Anna

    2011-10-01

    Bryophyte species composition and 26 common physico-chemical and inorganic chemical parameters were assessed at 23 selected sites in the Maritsa River (BG) over a 4-year period. Principal components analyses (PCA) of both bryophytes and water variables distinguished different locations in the ecosystem. The data imply that the content of elements measured in bryophytes represents river contamination, while species compositional patterns reflect hydromorphology and general degradation. This study for the first time combined aquatic bryophyte occurrence, the bioaccumulation of 17 macro-and microelements in 17 species, and 26 water factors by principal components analysis (PCA) in an assessment of river pollution.

  12. Aquatic risk assessment of pesticides in Latin America.

    Science.gov (United States)

    Carriquiriborde, Pedro; Mirabella, Paula; Waichman, Andrea; Solomon, Keith; Van den Brink, Paul J; Maund, Steve

    2014-10-01

    Latin America is anticipated to be a major growth market for agriculture and production is increasing with use of technologies such as pesticides. Reports of contamination of aquatic ecosystems by pesticides in Latin America have raised concerns about potential for adverse ecological effects. In the registration process of pesticides, all countries require significant data packages on aquatic toxicology and environmental fate. However, there are usually no specific requirements to conduct an aquatic risk assessment. To address this issue, the Society of Environmental Toxicology and Chemistry organized a workshop that brought together scientists from academia, government, and industry to review and elaborate on aquatic risk assessment frameworks that can be implemented into regulation of pesticides in Latin America. The workshop concluded that the international framework for risk assessments (protection goals, effects, and exposure assessments, risk characterization, and risk mitigation) is broadly applicable in Latin America but needs further refinement for the use in the region. Some of the challenges associated with these refinements are discussed in the article. It was recognized that there is potential for data sharing both within and outside of the region where conditions are similar. However, there is a need for research to compare local species and environmental conditions to those in other jurisdictions to be able to evaluate the applicability of data used in other countries. Development should also focus on human resources as there is a need to build local capacity and capability, and scientific collaboration and exchange between stakeholders in industry, government, and academia is also important. The meeting also emphasized that, although establishing a regionally relevant risk assessment framework is important, this also needs to be accompanied by enforcement of developed regulations and good management practices to help protect aquatic habitats

  13. Aquatic pathways model to predict the fate of phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Aaberg, R.L.; Peloquin, R.A.; Strenge, D.L.; Mellinger, P.J.

    1983-04-01

    Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with parameters for distribution of phenols, an important class of compounds found in the water-soluble fractions of coal liquids. Current modeling efforts show that, in comparison with many pesticides and polyaromatic hydrocarbons (PAH), the lighter phenolics (the cresols) are not persistent in the environment. The properties of heavier molecular weight phenolics (indanols, naphthols) are not well enough understood at this time to make similar judgements. For the twelve phenolics studied, biodegradation appears to be the major pathway for elimination from aquatic environments. A pond system simulation (using APM) of a spill of solvent refined coal (SRC-II) materials indicates that phenol, cresols, and other single cyclic phenolics are degraded to 16 to 25 percent of their original concentrations within 30 hours. Adsorption of these compounds into sediments and accumulation by fish was minor.

  14. Range Ecosystems

    Science.gov (United States)

    After 200 years, livestock grazing remains California’s most extensive land use. Contemporary rangelands are managed for multiple outcomes, including livestock production, biodiversity conservation, fuels management, and soil, water, and air quality protection. The requirements of grazing management...

  15. Marine and other aquatic dermatoses

    Directory of Open Access Journals (Sweden)

    Jandhyala Sridhar

    2017-01-01

    Full Text Available Occupational and recreational aquatic activity predisposes our population to a wide variety of dermatoses. Sunburn, urticaria, jellyfish stings, and contact dermatitis to rubber equipment are common allergies that are encountered in the aquatic environment. Among the infections, tinea versicolor, intertrigo, and verruca vulgaris are widespread. Swimmer's itch may occur due to skin penetration by schistosome cercariae, while free-floating nematocysts of marine coelenterates may precipitate seabather's eruption. “Suit squeeze” due to cutaneous barotrauma and lymphoedematous peau d'orange due to decompression are rare, described entities. This review serves as a ready reckoner for Indian dermatologists and medical practitioners to identify and manage these conditions.

  16. Biomass or growth rate endpoint for algae and aquatic plants: relevance for the aquatic risk assessment of herbicides.

    Science.gov (United States)

    Bergtold, Matthias; Dohmen, Gerhard Peter

    2011-04-01

    Ecotoxicological studies with algae and aquatic plants are essential parts of the aquatic risk assessment for crop protection products (CPP). Growth rate is used as a response variable and in addition the effects on biomass and/or yield (in the following biomass) can be measured. The parameter biomass generally provides a lower numerical value compared with the growth rate for systematic and mathematical reasons. Therefore, some regulators prefer to use the EbC50 value (i.e., the concentration at which 50% reduction of biomass is observed) rather than ErC50 (the concentration at which a 50% inhibition of growth rate is observed) as the endpoint for ecotoxicological risk assessment. However, the parameter growth rate is scientifically more appropriate and robust against deviations in test conditions, permitting better interpretation of, and comparison between, studies. The aim of the present work is to evaluate the growth rate and biomass parameters with regard to their protectiveness and suitability for environmental risk assessment of CPP. It has been shown for a number of herbicides that the use of the EC50 value (without distinction between growth rate and biomass endpoints) from laboratory studies in combination with an assessment factor of 10 is sufficiently protective for aquatic plants (except for the herbicide 2,4-D). In this paper we evaluated EbC50 and ErC50 values separately. Data on 19 different herbicides were compiled from the literature or GLP reports. The EbC50 and ErC50 values obtained in laboratory studies were compared with effect concentrations in ecosystem studies (mainly mesocosm). This comparison of laboratory and field data shows that the overall aquatic risk assessment using ErC50 values in combination with the currently applied assessment factor of 10 is sufficient to exclude significant risk to aquatic plants in the environment.

  17. Focusing on variation: methods and applications of the concept of beta diversity in aquatic ecosystems Focando na variação: métodos e aplicações do conceito de diversidade beta em ecossistemas aquáticos

    Directory of Open Access Journals (Sweden)

    Adriano Sanches Melo

    2011-09-01

    Full Text Available Ecologists usually estimate means, but devote much less attention to variation. The study of variation is a key aspect to understand natural systems and to make predictions regarding them. In community ecology, most studies focus on local species diversity (alpha diversity, but only in recent decades have ecologists devoted proper attention to variation in community composition among sites (beta diversity. This is in spite of the fact that the first attempts to estimate beta diversity date back to the pioneering work by Koch and Whittaker in the 1950s. Progress in the last decade has been made in the development both of methods and of hypotheses about the origin and maintenance of variation in community composition. For instance, methods are available to partition total diversity in a region (gamma diversity, in a local component (alpha, and several beta diversities, each corresponding to one scale in a hierarchy. The popularization of the so-called raw-data approach (based on partial constrained ordination techniques and the distance-based approach (based on correlation of dissimilarity/distance matrices have allowed many ecologists to address current hypotheses about beta diversity patterns. Overall, these hypotheses are based on niche and neutral theory, accounting for the relative roles of environmental and spatial processes (or a combination of them in shaping metacommunities. Recent studies have addressed these issues on a variety of spatial and temporal scales, habitats and taxonomic groups. Moreover, life history and functional traits of species such as dispersal abilities and rarity have begun to be considered in studies of beta diversity. In this article we briefly review some of these new tools and approaches developed in recent years, and illustrate them by using case studies in aquatic ecosystems.Ecólogos geralmente estimam médias, mas dedicam pouca atenção à variação. O estudo da variação é um aspecto chave para entender

  18. Biosecurity in aquatic animal facilities: concepts and examples

    Science.gov (United States)

    Biosecurity includes measures to minimize the risk of introduction and spread of infectious organisms within or between aquatic animal populations. Biosecurity measures at the site level include bioexclusion, within-site infectious disease control and biocontainment. This talk will focus on bioexclu...

  19. Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

    Science.gov (United States)

    Jorien E. Vonk,; Tank, Suzanne E.; Paul J. Mann,; Robert G.M. Spencer,; Treat, Claire C.; Striegl, Robert G.; Benjamin W. Abbott,; Wickland, Kimberly P.

    2015-01-01

    As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to