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Christiane Zarfl
Center for Applied Geoscience, Eberhard Karls University of Tübingen, Schnarrenbergstr. 94−96, 72076 Tübingen, Germany

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Research article
Published: 24 March 2021 in Environmental Science & Technology
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Suspended particulate matter (SPM) plays an important role in the fate of organic micropollutants in rivers during rain events, when sediments are remobilized and turbid runoff components enter the rivers. Under baseflow conditions, the SPM concentration is low and the contribution of SPM-bound contaminants to the overall risk of organic contaminants in rivers is assumed to be negligible. To challenge this assumption, we explored if SPM may act as a source or sink for all or specific groups of organic chemicals in a small river. The concentrations of over 600 contaminants and the mixture effects stemming from all chemicals in in vitro bioassays were measured for river water, SPM, and the surface sediment after solid-phase extraction or exhaustive solvent extraction. The bioavailable fractions of chemicals and mixture effects were estimated after passive equilibrium sampling of enriched SPM slurries and sediments in the lab. Dissolved compounds dominated the total chemical burden in the water column (water plus SPM) of the river, whereas SPM-bound chemicals contributed up to 46% of the effect burden even if the SPM concentration in rivers was merely 1 mg/L. The equilibrium between water and SPM was still not reached under low-flow conditions with SPM as a source of water contamination. The ratios of SPM-associated to sediment-associated neutral and hydrophobic chemicals as well as the ratios of the mixture effects expressed as bioanalytical equivalent concentrations were close to 1, suggesting that the surface sediment can be used as a proxy for SPM under baseflow conditions when the sampling of a large amount of water to obtain sufficient SPM cannot be realized.

ACS Style

Lili Niu; Jörg Ahlheim; Clarissa Glaser; Roman Gunold; Luise Henneberger; Maria König; Martin Krauss; Marc Schwientek; Christiane Zarfl; Beate I. Escher. Suspended Particulate Matter—A Source or Sink for Chemical Mixtures of Organic Micropollutants in a Small River under Baseflow Conditions? Environmental Science & Technology 2021, 55, 5106 -5116.

AMA Style

Lili Niu, Jörg Ahlheim, Clarissa Glaser, Roman Gunold, Luise Henneberger, Maria König, Martin Krauss, Marc Schwientek, Christiane Zarfl, Beate I. Escher. Suspended Particulate Matter—A Source or Sink for Chemical Mixtures of Organic Micropollutants in a Small River under Baseflow Conditions? Environmental Science & Technology. 2021; 55 (8):5106-5116.

Chicago/Turabian Style

Lili Niu; Jörg Ahlheim; Clarissa Glaser; Roman Gunold; Luise Henneberger; Maria König; Martin Krauss; Marc Schwientek; Christiane Zarfl; Beate I. Escher. 2021. "Suspended Particulate Matter—A Source or Sink for Chemical Mixtures of Organic Micropollutants in a Small River under Baseflow Conditions?" Environmental Science & Technology 55, no. 8: 5106-5116.

Journal article
Published: 01 February 2021 in Sustainability
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Mitigating climate change, while human population and economy are growing globally, requires a bold shift to renewable energy sources. Among renewables, hydropower is currently the most economic and efficient technique. However, due to a lack of impact assessments at the catchment scale in the planning process, the construction of hydropower plants (HPP) may have unexpected ecological, socioeconomic, and political ramifications in the short and in the long term. The Vjosa River, draining parts of Northern Greece and Albania, is one of the few predominantly free-flowing rivers left in Europe; at the same time its catchment is identified an important resource for future hydropower development. While current hydropower plants are located along tributaries, planned HPP would highly impact the free-flowing main stem. Taking the Vjosa catchment as a case study, the aim of this study was to develop a transferable impact assessment that ranks potential hydropower sites according to their projected impacts on a catchment scale. Therefore, we integrated established ecological, social, and economic indicators for all HPP planned in the river catchment, while considering their capacity, and developed a ranking method based on impact categories. For the Vjosa catchment, ten hydropower sites were ranked as very harmful to the environment as well as to society. A sensitivity analysis revealed that this ranking is dependent upon the selection of indicators. Small HPP showed higher cumulative impacts than large HPP, when normalized to capacity. This study empowers decision-makers to compare both the ranked impacts and the generated energy of planned dam projects at the catchment scale.

ACS Style

Rebecca Peters; Jürgen Berlekamp; Ana Lucía; Vittoria Stefani; Klement Tockner; Christiane Zarfl. Integrated Impact Assessment for Sustainable Hydropower Planning in the Vjosa Catchment (Greece, Albania). Sustainability 2021, 13, 1514 .

AMA Style

Rebecca Peters, Jürgen Berlekamp, Ana Lucía, Vittoria Stefani, Klement Tockner, Christiane Zarfl. Integrated Impact Assessment for Sustainable Hydropower Planning in the Vjosa Catchment (Greece, Albania). Sustainability. 2021; 13 (3):1514.

Chicago/Turabian Style

Rebecca Peters; Jürgen Berlekamp; Ana Lucía; Vittoria Stefani; Klement Tockner; Christiane Zarfl. 2021. "Integrated Impact Assessment for Sustainable Hydropower Planning in the Vjosa Catchment (Greece, Albania)." Sustainability 13, no. 3: 1514.

Contributed paper
Published: 16 July 2020 in Conservation Biology
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Megafauna species are intrinsically vulnerable to human impact. Freshwater megafauna, i.e. freshwater animals ≥ 30 kg, including fishes, mammals, reptiles, and amphibians, are subject to intensive and increasing threats, with 34 species listed as Critically Endangered on the IUCN Red List. IUCN Red List assessments are an important basis for conservation actions but remain incomplete for 49 (24%) freshwater megafauna species. Consequently, the window of opportunity for protecting these species could be missed. Identifying the factors that predispose freshwater megafauna to extinction can help predict their extinction risk and facilitate more effective and proactive conservation actions. Thus, we collated eight life‐history traits for 206 freshwater megafauna species. We used generalized linear mixed models to examine the relationships between extinction risk measured as the IUCN Red List categories and the combined effect of multiple traits, as well as the influence of human impact on these relationships, for 157 classified species. The most parsimonious model included human impact and traits related to species’ recovery potential including lifespan, age at maturity, and fecundity. Applying the most parsimonious model to 49 unclassified species predicted that 17 of them are threatened. Accounting for model predictions together with IUCN Red List assessments, 50% of all freshwater megafauna species are considered as threatened. The Amazon and Yangtze basins emerged as global diversity hotspots of threatened freshwater megafauna, in addition to existing hotspots including the Ganges‐Brahmaputra, Congo, and Mekong basins and the Caspian Sea region. Assessment and monitoring of those freshwater megafauna species predicted as threatened are needed, especially in the Amazon and Yangtze basins. Investigation of life‐history traits and trends in population and distribution, regulation of overexploitation, maintaining river connectivity, implementing protected areas focusing on freshwater ecosystems, and integrated basin management are required to protect threatened freshwater megafauna in diversity hotspots. Article Impact Statement : Life‐history traits and human impact jointly determine extinction risk of freshwater megafauna. This article is protected by copyright. All rights reserved

ACS Style

Fengzhi He; Simone D. Langhans; Christiane Zarfl; Roland Wanke; Klement Tockner; Sonja C. Jähnig. Combined effects of life‐history traits and human impact on extinction risk of freshwater megafauna. Conservation Biology 2020, 35, 643 -653.

AMA Style

Fengzhi He, Simone D. Langhans, Christiane Zarfl, Roland Wanke, Klement Tockner, Sonja C. Jähnig. Combined effects of life‐history traits and human impact on extinction risk of freshwater megafauna. Conservation Biology. 2020; 35 (2):643-653.

Chicago/Turabian Style

Fengzhi He; Simone D. Langhans; Christiane Zarfl; Roland Wanke; Klement Tockner; Sonja C. Jähnig. 2020. "Combined effects of life‐history traits and human impact on extinction risk of freshwater megafauna." Conservation Biology 35, no. 2: 643-653.

Journal article
Published: 23 June 2020 in Water
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Urban areas are a leading source of polycyclic aromatic hydrocarbons (PAHs) that result from combustion processes and are emitted into rivers, especially during rain events and with particle wash-off from urban surfaces. In-stream transport of suspended particles and attached PAHs is linked strongly to sediment turnover processes. This study aimed to identify particle exchange processes that contribute to the transport of suspended particles during flood events. An urban high-flow signal was tracked in high temporal resolution at two sampling sites in the Ammer River (South-western Germany). Samples were analyzed for turbidity, total suspended solids concentrations (TSS), particle-size distribution, organic carbon, and PAH. Maximum discharge and the highest TSS occurred nearly simultaneously at the upstream sampling site, whereas a temporally shifted course was observed for downstream. The total load of particles was similar, yet a decrease of PAH mass (~28%) and an increase of the particulate organic carbon (POC) content (~3.5%-points) occurred. Coarser particles (≥26 µm) dominated at the beginning of the event at both sampling sites. The signal of remobilized riverbed sediment increases downstream and leads to well-established, robust linear correlations between TSS and PAHs. This study highlights that riverbed sediment acts as intermediate storage for contaminated particles from upstream sources that shape, together with the fresh urban input, the “particle signature” of suspensions moving through catchments during high discharge conditions.

ACS Style

Clarissa Glaser; Christiane Zarfl; Hermann Rügner; Amelia Lewis; Marc Schwientek. Analyzing Particle-Associated Pollutant Transport to Identify In-Stream Sediment Processes During a High Flow Event. Water 2020, 12, 1794 .

AMA Style

Clarissa Glaser, Christiane Zarfl, Hermann Rügner, Amelia Lewis, Marc Schwientek. Analyzing Particle-Associated Pollutant Transport to Identify In-Stream Sediment Processes During a High Flow Event. Water. 2020; 12 (6):1794.

Chicago/Turabian Style

Clarissa Glaser; Christiane Zarfl; Hermann Rügner; Amelia Lewis; Marc Schwientek. 2020. "Analyzing Particle-Associated Pollutant Transport to Identify In-Stream Sediment Processes During a High Flow Event." Water 12, no. 6: 1794.

Letter
Published: 22 May 2020 in Conservation Letters
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Protected areas (PAs) are an essential tool for freshwater biodiversity conservation. Given past and expected future global increases in dams and impacts of dams on freshwater ecosystems, we document the number of dams existing or planned within PAs, their history, and the extent of PA downgrading, downsizing, and degazettement (PADDD) proximally caused by dams. Globally, at least 1,249 large dams are located within PAs; two‐thirds (907) were built before PA establishment. Additionally, 14% of planned geolocated hydropower dams (509 dams) are located within PAs. PADDD events have also legalized dam construction within existing PAs. Environmental safeguards should preclude development of dams within or adjacent to PAs and prioritize dams within PAs for possible removal and restoration.

ACS Style

Michele L. Thieme; Dmytro Khrystenko; Siyu Qin; Rachel E. Golden Kroner; Bernhard Lehner; Shalynn Pack; Klement Tockner; Christiane Zarfl; Natalie Shahbol; Michael B. Mascia. Dams and protected areas: Quantifying the spatial and temporal extent of global dam construction within protected areas. Conservation Letters 2020, 13, 1 .

AMA Style

Michele L. Thieme, Dmytro Khrystenko, Siyu Qin, Rachel E. Golden Kroner, Bernhard Lehner, Shalynn Pack, Klement Tockner, Christiane Zarfl, Natalie Shahbol, Michael B. Mascia. Dams and protected areas: Quantifying the spatial and temporal extent of global dam construction within protected areas. Conservation Letters. 2020; 13 (4):1.

Chicago/Turabian Style

Michele L. Thieme; Dmytro Khrystenko; Siyu Qin; Rachel E. Golden Kroner; Bernhard Lehner; Shalynn Pack; Klement Tockner; Christiane Zarfl; Natalie Shahbol; Michael B. Mascia. 2020. "Dams and protected areas: Quantifying the spatial and temporal extent of global dam construction within protected areas." Conservation Letters 13, no. 4: 1.

Journal article
Published: 18 April 2020 in Water
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This paper presents interdisciplinary research focusing on the municipality of Braunsbach in the German state of Baden-Württemberg, where, in May 2016, a flash flood attracted media attention and scientific scrutiny that highlighted the fact that certain aspects of flood risk were overlooked during earlier assessments conducted by the municipality, such as sediment transport. Using a network analysis and a focus-group discussion, we traced the flow of knowledge through the reported interactions between governmental, private, and academic actors in the two and a half years after the event. From our analysis, we learned that the extreme event attracted scientists to the formal and informal assessment of the hazard and the associated damages. Most importantly, we found conditions under which scientific scrutiny is not detached from but becomes integrated in a governance setting. While it is through this process that sediment transport has become an integral part of flood-risk management in Baden-Württemberg, with an evident impact on the measures already implemented, the impact of morphological changes, as well as large wood and sediment transport, have not been factored into the risk assessment as of yet. These variations in scientific impact on the assessment can be explained by decision biases that can occur when decision makers are under pressure to tackle vulnerabilities and thus lack the time to deliberate in a way that uses all the available evidence.

ACS Style

Antje Witting; Frederik Brandenstein; Christiane Zarfl; Ana Lucía. Impact of Scientific Scrutiny after the 2016 Braunsbach Flash Flood on Flood-Risk Management in the State of Baden-Württemberg, Germany. Water 2020, 12, 1165 .

AMA Style

Antje Witting, Frederik Brandenstein, Christiane Zarfl, Ana Lucía. Impact of Scientific Scrutiny after the 2016 Braunsbach Flash Flood on Flood-Risk Management in the State of Baden-Württemberg, Germany. Water. 2020; 12 (4):1165.

Chicago/Turabian Style

Antje Witting; Frederik Brandenstein; Christiane Zarfl; Ana Lucía. 2020. "Impact of Scientific Scrutiny after the 2016 Braunsbach Flash Flood on Flood-Risk Management in the State of Baden-Württemberg, Germany." Water 12, no. 4: 1165.

Review article
Published: 04 March 2020 in Proceedings of the Royal Society of London. Series B: Biological Sciences
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Concern for megafauna is increasing among scientists and non-scientists. Many studies have emphasized that megafauna play prominent ecological roles and provide important ecosystem services to humanity. But, what precisely are ‘megafauna’? Here, we critically assess the concept of megafauna and propose a goal-oriented framework for megafaunal research. First, we review definitions of megafauna and analyse associated terminology in the scientific literature. Second, we conduct a survey among ecologists and palaeontologists to assess the species traits used to identify and define megafauna. Our review indicates that definitions are highly dependent on the study ecosystem and research question, and primarily rely on ad hoc size-related criteria. Our survey suggests that body size is crucial, but not necessarily sufficient, for addressing the different applications of the term megafauna. Thus, after discussing the pros and cons of existing definitions, we propose an additional approach by defining two function-oriented megafaunal concepts: ‘keystone megafauna’ and ‘functional megafauna’, with its variant ‘apex megafauna’. Assessing megafauna from a functional perspective could challenge the perception that there may not be a unifying definition of megafauna that can be applied to all eco-evolutionary narratives. In addition, using functional definitions of megafauna could be especially conducive to cross-disciplinary understanding and cooperation, improvement of conservation policy and practice, and strengthening of public perception. As megafaunal research advances, we encourage scientists to unambiguously define how they use the term ‘megafauna’ and to present the logic underpinning their definition.

ACS Style

Marcos Moleón; José A. Sánchez-Zapata; José A. Donázar; Eloy Revilla; Berta Martín-López; Cayetano Gutierrez Canovas; Wayne M. Getz; Zebensui Morales-Reyes; Ahimsa Campos-Arceiz; Larry B. Crowder; Mauro Galetti; Manuela Gonzalez Suarez; Fengzhi He; Pedro Jordano; Rebecca Lewison; Robin Naidoo; Norman Owen-Smith; Nuria Selva; Jens-Christian Svenning; José L. Tella; Christiane Zarfl; Sonja C. Jähnig; Matt W. Hayward; Søren Faurby; Nuria García; Anthony D. Barnosky; Klement Tockner. Rethinking megafauna. Proceedings of the Royal Society of London. Series B: Biological Sciences 2020, 287, 20192643 .

AMA Style

Marcos Moleón, José A. Sánchez-Zapata, José A. Donázar, Eloy Revilla, Berta Martín-López, Cayetano Gutierrez Canovas, Wayne M. Getz, Zebensui Morales-Reyes, Ahimsa Campos-Arceiz, Larry B. Crowder, Mauro Galetti, Manuela Gonzalez Suarez, Fengzhi He, Pedro Jordano, Rebecca Lewison, Robin Naidoo, Norman Owen-Smith, Nuria Selva, Jens-Christian Svenning, José L. Tella, Christiane Zarfl, Sonja C. Jähnig, Matt W. Hayward, Søren Faurby, Nuria García, Anthony D. Barnosky, Klement Tockner. Rethinking megafauna. Proceedings of the Royal Society of London. Series B: Biological Sciences. 2020; 287 (1922):20192643.

Chicago/Turabian Style

Marcos Moleón; José A. Sánchez-Zapata; José A. Donázar; Eloy Revilla; Berta Martín-López; Cayetano Gutierrez Canovas; Wayne M. Getz; Zebensui Morales-Reyes; Ahimsa Campos-Arceiz; Larry B. Crowder; Mauro Galetti; Manuela Gonzalez Suarez; Fengzhi He; Pedro Jordano; Rebecca Lewison; Robin Naidoo; Norman Owen-Smith; Nuria Selva; Jens-Christian Svenning; José L. Tella; Christiane Zarfl; Sonja C. Jähnig; Matt W. Hayward; Søren Faurby; Nuria García; Anthony D. Barnosky; Klement Tockner. 2020. "Rethinking megafauna." Proceedings of the Royal Society of London. Series B: Biological Sciences 287, no. 1922: 20192643.

Journal article
Published: 06 December 2019 in Scientific Reports
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Dam construction comes with severe social, economic and ecological impacts. From an ecological point of view, habitat types are altered and biodiversity is lost. Thus, to identify areas that deserve major attention for conservation, existing and planned locations for (hydropower) dams were overlapped, at global extent, with the contemporary distribution of freshwater megafauna species with consideration of their respective threat status. Hydropower development will disproportionately impact areas of high freshwater megafauna richness in South America, South and East Asia, and the Balkan region. Sub-catchments with a high share of threatened species are considered to be most vulnerable; these are located in Central America, Southeast Asia and in the regions of the Black and Caspian Sea. Based on this approach, planned dam locations are classified according to their potential impact on freshwater megafauna species at different spatial scales, attention to potential conflicts between climate mitigation and biodiversity conservation are highlighted, and priorities for freshwater management are recommended.

ACS Style

Christiane Zarfl; Jürgen Berlekamp; Fengzhi He; Sonja C. Jähnig; William Darwall; Klement Tockner. Future large hydropower dams impact global freshwater megafauna. Scientific Reports 2019, 9, 1 -10.

AMA Style

Christiane Zarfl, Jürgen Berlekamp, Fengzhi He, Sonja C. Jähnig, William Darwall, Klement Tockner. Future large hydropower dams impact global freshwater megafauna. Scientific Reports. 2019; 9 (1):1-10.

Chicago/Turabian Style

Christiane Zarfl; Jürgen Berlekamp; Fengzhi He; Sonja C. Jähnig; William Darwall; Klement Tockner. 2019. "Future large hydropower dams impact global freshwater megafauna." Scientific Reports 9, no. 1: 1-10.

Research article
Published: 09 June 2019 in Environmental Science & Technology
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The aim of the current study was to understand and develop models to predict the pH-dependent toxicity of ionizable pharmaceuticals in embryos of the zebrafish Danio rerio. We found a higher uptake and toxicity with increasing neutral fraction of acids (diclofenac, genistein, naproxen, torasemide, and warfarin) and bases (metoprolol and propranolol). Simple mass balance models accounting for the partitioning to lipids and proteins in the zebrafish embryo were found to be suitable to predict the bioconcentration after 96 h of exposure if pH-values did not differ much from the internal pH of 7.55. For other pH-values, a kinetic ion-trap model for the zebrafish embryo explained the pH-dependence of biouptake and toxicity. The total internal lethal concentrations killing 50% of the zebrafish embryos (ILC50) were calculated from the measured BCF and LC50. The resulting ILC50 were independent of external pH. Critical membrane concentrations were deduced by an internal mass balance model and apart from diclofenac, whose specific toxicity in fish had already been established, all pharmaceuticals were confirmed to act as baseline toxicants in zebrafish.

ACS Style

Lisa Bittner; Nils Klüver; Luise Henneberger; Marie Muehlenbrink; Christiane Zarfl; Beate I. Escher. Combined Ion-Trapping and Mass Balance Models To Describe the pH-Dependent Uptake and Toxicity of Acidic and Basic Pharmaceuticals in Zebrafish Embryos (Danio rerio). Environmental Science & Technology 2019, 53, 7877 -7886.

AMA Style

Lisa Bittner, Nils Klüver, Luise Henneberger, Marie Muehlenbrink, Christiane Zarfl, Beate I. Escher. Combined Ion-Trapping and Mass Balance Models To Describe the pH-Dependent Uptake and Toxicity of Acidic and Basic Pharmaceuticals in Zebrafish Embryos (Danio rerio). Environmental Science & Technology. 2019; 53 (13):7877-7886.

Chicago/Turabian Style

Lisa Bittner; Nils Klüver; Luise Henneberger; Marie Muehlenbrink; Christiane Zarfl; Beate I. Escher. 2019. "Combined Ion-Trapping and Mass Balance Models To Describe the pH-Dependent Uptake and Toxicity of Acidic and Basic Pharmaceuticals in Zebrafish Embryos (Danio rerio)." Environmental Science & Technology 53, no. 13: 7877-7886.

Review
Published: 27 March 2019 in Analytical and Bioanalytical Chemistry
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Microplastics are observed ubiquitously and in different environmental compartments ranging from marine waters and sediments to freshwater and terrestrial ecosystems including biota. Over the last decade, several methods have been applied and advanced to monitor and quantify microplastics, to identify the polymer material and to describe the particle properties, such as size, shape or colour. In most cases, the overarching aim is to elucidate patterns of occurrence that might result from (micro)plastic emissions and environmental fate. But the applied methods are subject to uncertainties and boundary conditions, be it spatial resolution that excludes the smallest microplastics or limitations in distinguishing microplastic particles from natural particles. This critical review provides an overview of the state-of-the-art procedures in microplastic analysis, gives examples of potential ways ahead and remaining challenges and classifies available methods according to the underlying research question. The resulting decision tree for the selection of analytical methods starts with a common research question and takes specificities of the environmental matrix into account. The procedural range consequently ranges from fast screening methods based on visual identification to a highly sophisticated combination of analytical methods that provide information on polymer type, particle number or mass and eventually particle size but are very time-consuming and expensive. Standardization of microplastic analytical methods on the basis of the research aim will help to make study results comparable and obtain a more comprehensive picture of microplastic abundance and fate in the environment.

ACS Style

Christiane Zarfl. Promising techniques and open challenges for microplastic identification and quantification in environmental matrices. Analytical and Bioanalytical Chemistry 2019, 411, 3743 -3756.

AMA Style

Christiane Zarfl. Promising techniques and open challenges for microplastic identification and quantification in environmental matrices. Analytical and Bioanalytical Chemistry. 2019; 411 (17):3743-3756.

Chicago/Turabian Style

Christiane Zarfl. 2019. "Promising techniques and open challenges for microplastic identification and quantification in environmental matrices." Analytical and Bioanalytical Chemistry 411, no. 17: 3743-3756.

Primary research article
Published: 09 January 2019 in Global Change Biology
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Climate change and human pressures are changing the global distribution and the extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experimentally simulated, under standard laboratory conditions, rewetting of leaves, riverbed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative characteristics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dissolved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contributed most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental variables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached substances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying events.

ACS Style

Oleksandra Shumilova; Dominik Zak; Thibault Datry; Daniel Von Schiller; Roland Corti; Arnaud Foulquier; Biel Obrador; Klement Tockner; Daniel C. Allan; Florian Altermatt; Maria Isabel Arce; Shai Arnon; Damien Banas; Andy Banegas‐Medina; Erin Beller; Melanie Blanchette; Juan F. Blanco‐Libreros; Joanna Blessing; Iola Gonçalves Boëchat; Kate Boersma; Michael T. Bogan; Núria Bonada; Nick R. Bond; Kate Brintrup; Andreas Bruder; Ryan Burrows; Tommaso Cancellario; Stephanie M. Carlson; Sophie Cauvy‐Fraunié; Núria Cid; Michael Danger; Bianca De Freitas Terra; Anna Maria De Girolamo; Ruben Del Campo; Fiona Dyer; Arturo Elosegi; Emile Faye; Catherine Febria; Ricardo Figueroa; Brian Four; Mark O. Gessner; Pierre Gnohossou; Rosa Gómez Cerezo; Lluís Gomez‐Gener; Manuel A.S. Graça; Simone Guareschi; Björn Gücker; Jason L. Hwan; Skhumbuzo Kubheka; Simone Daniela Langhans; Catherine Leigh; Chelsea J. Little; Stefan Lorenz; Jonathan Marshall; Angus McIntosh; Clara Mendoza‐Lera; Elisabeth Irmgard Meyer; Marko Miliša; Musa C. Mlambo; Marcos Moleón; Peter Negus; Dev Niyogi; Athina Papatheodoulou; Isabel Pardo; Petr Paril; Vladimir Pešić; Pablo Rodriguez‐Lozano; Robert J. Rolls; Maria Mar Sanchez‐Montoya; Ana Savić; Alisha Steward; Rachel Stubbington; Amina Taleb; Ross Vander Vorste; Nathan Waltham; Annamaria Zoppini; Christiane Zarfl. Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter. Global Change Biology 2019, 25, 1591 -1611.

AMA Style

Oleksandra Shumilova, Dominik Zak, Thibault Datry, Daniel Von Schiller, Roland Corti, Arnaud Foulquier, Biel Obrador, Klement Tockner, Daniel C. Allan, Florian Altermatt, Maria Isabel Arce, Shai Arnon, Damien Banas, Andy Banegas‐Medina, Erin Beller, Melanie Blanchette, Juan F. Blanco‐Libreros, Joanna Blessing, Iola Gonçalves Boëchat, Kate Boersma, Michael T. Bogan, Núria Bonada, Nick R. Bond, Kate Brintrup, Andreas Bruder, Ryan Burrows, Tommaso Cancellario, Stephanie M. Carlson, Sophie Cauvy‐Fraunié, Núria Cid, Michael Danger, Bianca De Freitas Terra, Anna Maria De Girolamo, Ruben Del Campo, Fiona Dyer, Arturo Elosegi, Emile Faye, Catherine Febria, Ricardo Figueroa, Brian Four, Mark O. Gessner, Pierre Gnohossou, Rosa Gómez Cerezo, Lluís Gomez‐Gener, Manuel A.S. Graça, Simone Guareschi, Björn Gücker, Jason L. Hwan, Skhumbuzo Kubheka, Simone Daniela Langhans, Catherine Leigh, Chelsea J. Little, Stefan Lorenz, Jonathan Marshall, Angus McIntosh, Clara Mendoza‐Lera, Elisabeth Irmgard Meyer, Marko Miliša, Musa C. Mlambo, Marcos Moleón, Peter Negus, Dev Niyogi, Athina Papatheodoulou, Isabel Pardo, Petr Paril, Vladimir Pešić, Pablo Rodriguez‐Lozano, Robert J. Rolls, Maria Mar Sanchez‐Montoya, Ana Savić, Alisha Steward, Rachel Stubbington, Amina Taleb, Ross Vander Vorste, Nathan Waltham, Annamaria Zoppini, Christiane Zarfl. Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter. Global Change Biology. 2019; 25 (5):1591-1611.

Chicago/Turabian Style

Oleksandra Shumilova; Dominik Zak; Thibault Datry; Daniel Von Schiller; Roland Corti; Arnaud Foulquier; Biel Obrador; Klement Tockner; Daniel C. Allan; Florian Altermatt; Maria Isabel Arce; Shai Arnon; Damien Banas; Andy Banegas‐Medina; Erin Beller; Melanie Blanchette; Juan F. Blanco‐Libreros; Joanna Blessing; Iola Gonçalves Boëchat; Kate Boersma; Michael T. Bogan; Núria Bonada; Nick R. Bond; Kate Brintrup; Andreas Bruder; Ryan Burrows; Tommaso Cancellario; Stephanie M. Carlson; Sophie Cauvy‐Fraunié; Núria Cid; Michael Danger; Bianca De Freitas Terra; Anna Maria De Girolamo; Ruben Del Campo; Fiona Dyer; Arturo Elosegi; Emile Faye; Catherine Febria; Ricardo Figueroa; Brian Four; Mark O. Gessner; Pierre Gnohossou; Rosa Gómez Cerezo; Lluís Gomez‐Gener; Manuel A.S. Graça; Simone Guareschi; Björn Gücker; Jason L. Hwan; Skhumbuzo Kubheka; Simone Daniela Langhans; Catherine Leigh; Chelsea J. Little; Stefan Lorenz; Jonathan Marshall; Angus McIntosh; Clara Mendoza‐Lera; Elisabeth Irmgard Meyer; Marko Miliša; Musa C. Mlambo; Marcos Moleón; Peter Negus; Dev Niyogi; Athina Papatheodoulou; Isabel Pardo; Petr Paril; Vladimir Pešić; Pablo Rodriguez‐Lozano; Robert J. Rolls; Maria Mar Sanchez‐Montoya; Ana Savić; Alisha Steward; Rachel Stubbington; Amina Taleb; Ross Vander Vorste; Nathan Waltham; Annamaria Zoppini; Christiane Zarfl. 2019. "Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter." Global Change Biology 25, no. 5: 1591-1611.

Original research article
Published: 12 December 2018 in Frontiers in Environmental Science
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Globally, freshwater is unevenly distributed, both in space and time. Climate change, land use alteration, and increasing human exploitation will further increase the pressure on water as a resource for human welfare and on inland water ecosystems. Water transfer megaprojects (WTMP) are defined here as large-scale engineering interventions to divert water within and between river basins that meet one of the following criteria: construction costs >US$ 1 billion, distance of transfer >190 km, or volume of water transferred exceeds 0.23 km3 per year. WTMP represent an engineered solution to cope with water scarcity. These projects are most commonly associated with large-scale agricultural and energy development schemes, and many of them serve multiple purposes. Despite numerous case studies that focus on the social, economic, and environmental impacts of individual water transfer megaprojects, a global inventory of existing, planned and proposed projects is lacking. We carried out the first comprehensive global inventory of WTMP that are planned, proposed or under construction. We collected key information (e.g., location, distance, volume, costs, purpose) on 34 existing and 76 future (planned, proposed or under construction) WTMP. If realized, the total volume of water transferred by future projects will reach 1,910 km3 per year with a total transfer distance of more than twice the length of the Earth's equator. The largest future WTMP are located in North America, Asia, and Africa and the predicted total investment will exceed 2.7 trillion US$. Among future projects, 42 are for agricultural development, 13 for hydropower development and 10 combine both purposes. Future megaprojects are also planned to support mining, ecosystem restoration and navigation. Our results underscore the extent to which humans have and are planning to re-engineer the global hydrological network and flows through WTMP, creating a network of “artificial rivers.” They emphasize the need to ensure the inclusion of these projects in global and basin hydrological models, and to develop internationally agreed criteria to assess the ecological, social and economic impacts of WTMP.

ACS Style

Oleksandra Shumilova; Klement Tockner; Michele Thieme; Anna Koska; Christiane Zarfl. Global Water Transfer Megaprojects: A Potential Solution for the Water-Food-Energy Nexus? Frontiers in Environmental Science 2018, 6, 1 .

AMA Style

Oleksandra Shumilova, Klement Tockner, Michele Thieme, Anna Koska, Christiane Zarfl. Global Water Transfer Megaprojects: A Potential Solution for the Water-Food-Energy Nexus? Frontiers in Environmental Science. 2018; 6 ():1.

Chicago/Turabian Style

Oleksandra Shumilova; Klement Tockner; Michele Thieme; Anna Koska; Christiane Zarfl. 2018. "Global Water Transfer Megaprojects: A Potential Solution for the Water-Food-Energy Nexus?" Frontiers in Environmental Science 6, no. : 1.

Journal article
Published: 01 November 2018 in Science of The Total Environment
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This work presents a post-event survey study, addressing the geomorphic response and large wood budget of two torrents, Grimmbach and Orlacher Bach, in southwestern Germany that were affected by a flash flood on May 29, 2016. During the event, large amounts of wood clogged and damaged a bridge of a cycling path at the outlet of the Grimmbach, while the town of Braunsbach was devastated by discharge and material transported along the Orlacher Bach. The severity of the event in these two small catchments (30.0 km2 and 5.95 km2, respectively) is remarkable in basins with a relatively low average slope (10.7 and 12.0%, respectively). In order to gain a better understanding of the driving forces during this flood event an integrated approach was applied including (i) an estimate of peak discharges, (ii) an analysis of changes in channel width by comparing available aerial photographs before the flood with a post-flood aerial surveys with an Unmanned Aerial Vehicle and validation with field observations, (iii) a detailed mapping of landslides and analysis of their connectivity with the channel network and finally (iv) an analysis of the amounts of large wood recruited and deposited in the channel. The morphological changes in the channels can be explained by hydraulic parameters, such as stream power and unit stream power, and by morphological parameters such as the valley confinement. This is similar for LW recruitment amounts and volume of exported LW since most of it comes from the erosion of the valley floor. The morphological changes and large wood recruitment and deposit are in the range of studied mountain rivers. Both factors thus need to be considered for mapping and mitigating flash flood hazards also in this kind of low range mountains.

ACS Style

Ana Lucía; Marc Schwientek; Joachim Eberle; Christiane Zarfl. Planform changes and large wood dynamics in two torrents during a severe flash flood in Braunsbach, Germany 2016. Science of The Total Environment 2018, 640-641, 315 -326.

AMA Style

Ana Lucía, Marc Schwientek, Joachim Eberle, Christiane Zarfl. Planform changes and large wood dynamics in two torrents during a severe flash flood in Braunsbach, Germany 2016. Science of The Total Environment. 2018; 640-641 ():315-326.

Chicago/Turabian Style

Ana Lucía; Marc Schwientek; Joachim Eberle; Christiane Zarfl. 2018. "Planform changes and large wood dynamics in two torrents during a severe flash flood in Braunsbach, Germany 2016." Science of The Total Environment 640-641, no. : 315-326.

Journal article
Published: 01 November 2018 in Science of The Total Environment
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Regular sediment inputs are required for deltas to maintain their surface elevation relative to sea level, which is important for avoiding salinization, erosion, and flooding. However, fluvial sediment inputs to deltas are being threatened by changes in upstream catchments due to climate and land use change and, particularly, reservoir construction. In this research, the global hydrogeomorphic model WBMsed is used to project and contrast 'pristine' (no anthropogenic impacts) and 'recent' historical fluvial sediment delivery to the Ganges-Brahmaputra-Meghna, Mahanadi, and Volta deltas. Additionally, 12 potential future scenarios of environmental change comprising combinations of four climate and three socioeconomic pathways, combined with a single construction timeline for future reservoirs, were simulated and analysed. The simulations of the Ganges-Brahmaputra-Meghna delta showed a large decrease in sediment flux over time, regardless of future scenario, from 669 Mt/a in a 'pristine' world, through 566 Mt/a in the 'recent' past, to 79-92 Mt/a by the end of the 21st century across the scenarios (total average decline of 88%). In contrast, for the Mahanadi delta the simulated sediment delivery increased between the 'pristine' and 'recent' past from 23 Mt/a to 40 Mt/a (+77%), and then decreased to 7-25 Mt/a by the end of the 21st century. The Volta delta shows a large decrease in sediment delivery historically, from 8 to 0.3 Mt/a (96%) between the 'pristine' and 'recent' past, however over the 21st century the sediment flux changes little and is predicted to vary between 0.2 and 0.4 Mt/a dependent on scenario. For the Volta delta, catchment management short of removing or re-engineering the Volta dam would have little effect, however without careful management of the upstream catchments these deltas may be unable to maintain their current elevation relative to sea level, suggesting increasing salinization, erosion, flood hazards, and adaptation demands.

ACS Style

Frances E. Dunn; Robert J. Nicholls; Stephen E. Darby; Sagy Cohen; Christiane Zarfl; Balázs M. Fekete. Projections of historical and 21st century fluvial sediment delivery to the Ganges-Brahmaputra-Meghna, Mahanadi, and Volta deltas. Science of The Total Environment 2018, 642, 105 -116.

AMA Style

Frances E. Dunn, Robert J. Nicholls, Stephen E. Darby, Sagy Cohen, Christiane Zarfl, Balázs M. Fekete. Projections of historical and 21st century fluvial sediment delivery to the Ganges-Brahmaputra-Meghna, Mahanadi, and Volta deltas. Science of The Total Environment. 2018; 642 ():105-116.

Chicago/Turabian Style

Frances E. Dunn; Robert J. Nicholls; Stephen E. Darby; Sagy Cohen; Christiane Zarfl; Balázs M. Fekete. 2018. "Projections of historical and 21st century fluvial sediment delivery to the Ganges-Brahmaputra-Meghna, Mahanadi, and Volta deltas." Science of The Total Environment 642, no. : 105-116.

Journal article
Published: 14 August 2018 in Environmental Sciences Europe
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The contamination of aquatic ecosystems with both anthropogenic pollutants and particles in particular (microscopic) plastic debris items is of emerging concern. Since plastic particles can accumulate contaminants and potentially facilitate their transport, it is important to properly investigate sorption mechanisms. This is especially required for a large variety of chemicals that can be charged under environmental conditions and for which interactions with particles may hence go beyond mere partitioning. In this study, sorption experiments with two types of microplastic particles (polyethylene and polystyrene) and 19 different contaminants (pesticides, pharmaceuticals, and personal care products) were performed at three different pH values. We could show that sorption to plastic particles is stronger for hydrophobic compounds and that neutral species usually contribute more to the overall sorption. Bulk partitioning coefficients were in the same order of magnitude for polyethylene and polystyrene. Furthermore, our results confirm that partition coefficients for polar compounds can only be accurately determined if the solid-to-liquid ratio in batch experiments is more than 6–7 orders of magnitude higher than any plastic concentration detected in the environment. Consequently, only a minor fraction of pollutants in water bodies is associated with microplastics. Although neutral species primarily dominate the overall sorption, hydrophobic entities of ionic species cannot be neglected for some compounds. Notwithstanding, our results show that since microplastic concentrations as currently observed in the environment are very low, they are only a relevant sorbent for strongly hydrophobic but not for polar compounds.

ACS Style

Sven Seidensticker; Peter Grathwohl; Jonas Lamprecht; Christiane Zarfl. A combined experimental and modeling study to evaluate pH-dependent sorption of polar and non-polar compounds to polyethylene and polystyrene microplastics. Environmental Sciences Europe 2018, 30, 1 -12.

AMA Style

Sven Seidensticker, Peter Grathwohl, Jonas Lamprecht, Christiane Zarfl. A combined experimental and modeling study to evaluate pH-dependent sorption of polar and non-polar compounds to polyethylene and polystyrene microplastics. Environmental Sciences Europe. 2018; 30 (1):1-12.

Chicago/Turabian Style

Sven Seidensticker; Peter Grathwohl; Jonas Lamprecht; Christiane Zarfl. 2018. "A combined experimental and modeling study to evaluate pH-dependent sorption of polar and non-polar compounds to polyethylene and polystyrene microplastics." Environmental Sciences Europe 30, no. 1: 1-12.

Preprint content
Published: 03 August 2018
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ACS Style

Oleksandra Shumilova; Klement Tockner; Michele Thieme; Anna Koska; Christiane Zarfl. GLOBAL WATER TRANSFER MEGAPROJECTS: A SOLUTION FOR THE WATER-FOOD-ENERGY NEXUS? 2018, 1 .

AMA Style

Oleksandra Shumilova, Klement Tockner, Michele Thieme, Anna Koska, Christiane Zarfl. GLOBAL WATER TRANSFER MEGAPROJECTS: A SOLUTION FOR THE WATER-FOOD-ENERGY NEXUS? . 2018; ():1.

Chicago/Turabian Style

Oleksandra Shumilova; Klement Tockner; Michele Thieme; Anna Koska; Christiane Zarfl. 2018. "GLOBAL WATER TRANSFER MEGAPROJECTS: A SOLUTION FOR THE WATER-FOOD-ENERGY NEXUS?" , no. : 1.

Research article
Published: 19 July 2018 in Hydrology and Earth System Sciences
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Suspended sediments impact stream water quality by increasing the turbidity and acting as a vector for strongly sorbing pollutants. Understanding their sources is of great importance to developing appropriate river management strategies. In this study, we present an integrated sediment transport model composed of a catchment-scale hydrological model to predict river discharge, a river-hydraulics model to obtain shear stresses in the channel, a sediment-generating model, and a river sediment-transport model. We use this framework to investigate the sediment contributions from catchment and in-stream processes in the Ammer catchment close to Tübingen in southwestern Germany. The model is calibrated to stream flow and suspended-sediment concentrations. We use the monthly mean suspended-sediment load to analyze seasonal variations of different processes. The contributions of catchment and in-stream processes to the total loads are demonstrated by model simulations under different flow conditions. The evaluation of shear stresses by the river-hydraulics model allows the identification of hotspots and hot moments of bed erosion for the main stem of the Ammer River. The results suggest that the contributions of suspended-sediment loads from urban areas and in-stream processes are higher in the summer months, while deposition has small variations with a slight increase in summer months. The sediment input from agricultural land and urban areas as well as bed and bank erosion increase with an increase in flow rates. Bed and bank erosion are negligible when flow is smaller than the corresponding thresholds of 1.5 and 2.5 times the mean discharge, respectively. The bed-erosion rate is higher during the summer months and varies along the main stem. Over the simulated time period, net sediment trapping is observed in the Ammer River. The present work is the basis to study particle-facilitated transport of pollutants in the system, helping to understand the fate and transport of sediments and sediment-bound pollutants.

ACS Style

Yan Liu; Christiane Zarfl; Nandita B. Basu; Marc Schwientek; Olaf A. Cirpka. Contributions of catchment and in-stream processes to suspended sediment transport in a dominantly groundwater-fed catchment. Hydrology and Earth System Sciences 2018, 22, 3903 -3921.

AMA Style

Yan Liu, Christiane Zarfl, Nandita B. Basu, Marc Schwientek, Olaf A. Cirpka. Contributions of catchment and in-stream processes to suspended sediment transport in a dominantly groundwater-fed catchment. Hydrology and Earth System Sciences. 2018; 22 (7):3903-3921.

Chicago/Turabian Style

Yan Liu; Christiane Zarfl; Nandita B. Basu; Marc Schwientek; Olaf A. Cirpka. 2018. "Contributions of catchment and in-stream processes to suspended sediment transport in a dominantly groundwater-fed catchment." Hydrology and Earth System Sciences 22, no. 7: 3903-3921.

Journal article
Published: 18 June 2018 in Environmental Sciences Europe
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Rivers receive water and associated organic micropollutants from their entire catchment, including from urban, agricultural and natural sources, and constitute an important environmental component for catalyzing pollutant turnover. Environmental removal processes were extensively investigated under laboratory conditions in the past but there is still a lack of information on how organic micropollutants attenuate on the catchment scale. The aim of this study was to describe the chemical and toxicological profile of a 4th order river and to characterize in-stream processes. We propose indicator chemicals and indicator in vitro bioassays as screening methods to evaluate micropollutant input and transport and transformation processes of the chemical burden in a river. Carbamazepine and sulfamethoxazole were selected as indicators for dilution processes and the moderately degradable chemicals tramadol and sotalol as indicators for potential in-stream attenuation processes. The battery of bioassays covers seven environmentally relevant modes of action, namely estrogenicity, glucocorticogenic activity, androgenicity progestagenic activity and oxidative stress response, as well as activation of the peroxisome proliferator-activated receptor and the aryl hydrocarbon receptor, using the GeneBLAzer test battery and the AhR-CALUX and AREc32 assays. Both approaches, targeted chemical analysis and in vitro bioassays, identified a wastewater treatment plant (WWTP) as a major input source of organic micropollutants that dominantly influenced the water quality of the river. Downstream of the WWTP the amount of detected chemicals and biological effects decreased along the river flow. The organic indicator chemicals of known degradability uncovered dilution and potential loss processes in certain river stretches. The average cytotoxic potency of the river water decreased in a similar fashion as compounds of medium degradability such as the pharmaceutical sotalol. This study showed that the indicator chemical/indicator bioassay approach is suitable for identifying input sources of a mixture of organic micropollutants and to trace changes in the water quality along small rivers. This method forms the necessary basis for evaluating the natural attenuation processes of organic micropollutants on a catchment scale, especially when combined with enhanced sampling strategies in future studies.

ACS Style

Maximilian Müller; Beate I. Escher; Marc Schwientek; Martina Werneburg; Christiane Zarfl; Christian Zwiener. Combining in vitro reporter gene bioassays with chemical analysis to assess changes in the water quality along the Ammer River, Southwestern Germany. Environmental Sciences Europe 2018, 30, 1 -14.

AMA Style

Maximilian Müller, Beate I. Escher, Marc Schwientek, Martina Werneburg, Christiane Zarfl, Christian Zwiener. Combining in vitro reporter gene bioassays with chemical analysis to assess changes in the water quality along the Ammer River, Southwestern Germany. Environmental Sciences Europe. 2018; 30 (1):1-14.

Chicago/Turabian Style

Maximilian Müller; Beate I. Escher; Marc Schwientek; Martina Werneburg; Christiane Zarfl; Christian Zwiener. 2018. "Combining in vitro reporter gene bioassays with chemical analysis to assess changes in the water quality along the Ammer River, Southwestern Germany." Environmental Sciences Europe 30, no. 1: 1-14.

Biodiversity research
Published: 08 June 2018 in Diversity and Distributions
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Aim Freshwater megafauna remain underrepresented in research and conservation, despite a disproportionately high risk of extinction due to multiple human threats. Therefore, our aims are threefold; (i) identify global patterns of freshwater megafauna richness and endemism, (ii) assess the conservation status of freshwater megafauna and (iii) demonstrate spatial and temporal patterns of human pressure throughout their distribution ranges. Location Global. Methods We identified 207 extant freshwater megafauna species, based on a 30 kg weight threshold, and mapped their distributions using HydroBASINS subcatchments (level 8). Information on conservation status and population trends for each species was extracted from the IUCN Red List website. We investigated human impacts on freshwater megafauna in space and time by examining spatial congruence between their distributions and human pressures, described by the Incident Biodiversity Threat Index and Temporal Human Pressure Index. Results Freshwater megafauna occur in 76% of the world’s main river basins (level 3 HydroBASINS), with species richness peaking in the Amazon, Congo, Orinoco, Mekong and Ganges‐Brahmaputra basins. Freshwater megafauna are more threatened than their smaller counterparts within the specific taxonomic groups (i.e., fishes, mammals, reptiles and amphibians). Out of the 93 freshwater megafauna species with known population trends, 71% are in decline. Meanwhile, IUCN Red List assessments reported insufficient or outdated data for 43% of all freshwater megafauna species. Since the early 1990s, human pressure has increased throughout 63% of their distribution ranges, with particularly intense impacts occurring in the Mekong and Ganges‐Brahmaputra basins. Main conclusions Freshwater megafauna species are threatened globally, with intense and increasing human pressures occurring in many of their biodiversity hotspots. We call for research and conservation actions for freshwater megafauna, as they are highly sensitive to present and future pressures including a massive boom in hydropower dam construction in their biodiversity hotspots.

ACS Style

Fengzhi He; Vanessa Bremerich; Christiane Zarfl; Jonas Geldmann; Simone D. Langhans; Jonathan N. W. David; William Darwall; Klement Tockner; Sonja C. Jähnig. Freshwater megafauna diversity: Patterns, status and threats. Diversity and Distributions 2018, 24, 1395 -1404.

AMA Style

Fengzhi He, Vanessa Bremerich, Christiane Zarfl, Jonas Geldmann, Simone D. Langhans, Jonathan N. W. David, William Darwall, Klement Tockner, Sonja C. Jähnig. Freshwater megafauna diversity: Patterns, status and threats. Diversity and Distributions. 2018; 24 (10):1395-1404.

Chicago/Turabian Style

Fengzhi He; Vanessa Bremerich; Christiane Zarfl; Jonas Geldmann; Simone D. Langhans; Jonathan N. W. David; William Darwall; Klement Tockner; Sonja C. Jähnig. 2018. "Freshwater megafauna diversity: Patterns, status and threats." Diversity and Distributions 24, no. 10: 1395-1404.

Journal article
Published: 01 May 2018 in Science of The Total Environment
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Metals are concerning pollutants in estuaries, where contamination can undergo significant remobilisation driven by physico-chemical forcing. Environmental concentrations of metals in estuarine sediments are often higher than natural backgrounds, but show no contiguity to potential sources. Thus, better understanding the metal mobility in estuaries is essential to improve identification of pollution sources and their accountability for environmental effects. This study aims to identify the key biogeochemical drivers of metal mobilisation on contaminated estuarine sediments through (1) evaluation of the potential mobilisation under controlled conditions, and (2) investigation of the relevance of metal mobilisation for in situ pollution levels in an area with multiple contaminant sources. Sediments from a saltmarsh adjacent to a coastal landfill, a marina, and a shipyard on the Thames Estuary (Essex, UK) were exposed in the laboratory (24h, N=96, 20°C) to water under various salinity, pH, and redox potential. Major cations, Fe(II), and trace metal concentrations were analysed in the leachate and sediment. Salinity, pH and redox had a significant effect on metal mobilisation (p<0.001), e.g. under certain conditions Fe(II) leaching was increased ~1000-fold. Measurements in situ of surface and subsurface sediment cores revealed that landfill proximity poorly explained metal spatial distribution. However, physicochemical parameters explained up to 97% of geochemically normalized metal concentrations in sediments. Organic matter and pH were dominant factors for most of the metal concentrations at the sediment surface. At subsurface, major cations (Ca, Na, Mg and K) were determinant predictors of metal concentrations. Applying the empirical model obtained in the laboratory to geochemical conditions of the studied saltmarsh it was possible to demonstrate that Fe mobilisation regulates the fate of this (and other) metal in that area. Thus, present results highlight the importance of metal mobility to control sediment pollution and estuarine fate of metals.

ACS Style

Anderson Abel De Souza Machado; Kate Spencer; Christiane Zarfl; Francis O'Shea. Unravelling metal mobility under complex contaminant signatures. Science of The Total Environment 2018, 622-623, 373 -384.

AMA Style

Anderson Abel De Souza Machado, Kate Spencer, Christiane Zarfl, Francis O'Shea. Unravelling metal mobility under complex contaminant signatures. Science of The Total Environment. 2018; 622-623 ():373-384.

Chicago/Turabian Style

Anderson Abel De Souza Machado; Kate Spencer; Christiane Zarfl; Francis O'Shea. 2018. "Unravelling metal mobility under complex contaminant signatures." Science of The Total Environment 622-623, no. : 373-384.